This is more consistent with the current naming scheme (i.e. IsCallable
for callable bit on map, IsConstructor for constructor bit on map, and
now IsUndetectable for undetectable bit on map).
Also simplify the fallthrough case for Object::Equals, because we don't
need to check for Null or Undefined or Undetectable, as both Null and
Undefined already have the undetectable bit set on their maps.
R=machenbach@chromium.org
Review URL: https://codereview.chromium.org/1756413003
Cr-Commit-Position: refs/heads/master@{#34458}
This introduces a new instance type and reorders the JSObject types so any type requiring special LookupIterator support can be identified with a single range check.
In addition, it restructures the Next for better performance, avoiding unnecessary calls.
BUG=
Review URL: https://codereview.chromium.org/1751043002
Cr-Commit-Position: refs/heads/master@{#34429}
This relaxes the constraints of the optimized code map in order to be
able to update existing entries. It also simplifies the interface a
little bit. We can now insert an entry for a newly allocated literals
array together with previously cached context-independent code.
R=mvstanton@chromium.org
Review URL: https://codereview.chromium.org/1753213002
Cr-Commit-Position: refs/heads/master@{#34427}
Rename the existing (patching) ToBooleanStub to ToBooleanICStub to match
our naming convention, and add a new TurboFan-powered ToBooleanStub,
which just does the ToBoolean conversion without any runtime call or
code patching, so we can use it for Ignition (and TurboFan).
Drive-by-fix: Add an Oddball::to_boolean field similar to the ones we
already have for to_string and to_number, so we don't need to actually
dispatch on the concrete Oddball at all.
R=epertoso@chromium.org, rmcilroy@chromium.org, yangguo@chromium.org
Review URL: https://codereview.chromium.org/1744163002
Cr-Commit-Position: refs/heads/master@{#34361}
Since both null and undefined are also marked as undetectable now, we
can just test that bit instead of having the CompareNilIC try to collect
feedback to speed up the general case (without the undetectable bit
being used).
Drive-by-fix: Update the type system to match the new handling of
undetectable in the runtime.
R=danno@chromium.org
Committed: https://crrev.com/666aec0348c8793e61c8633dee7ad29a514239ba
Cr-Commit-Position: refs/heads/master@{#34237}
Review URL: https://codereview.chromium.org/1722193002
Cr-Commit-Position: refs/heads/master@{#34344}
The CompareICStub produces an untagged raw word value, which has to be
translated to true or false manually in the TurboFan code. But for lazy
bailout after the CompareIC, we immediately go back to fullcodegen or
Ignition with the raw value, to a location where both fullcodegen and
Ignition expect a boolean value, which might crash or in the worst case
(depending on the exact computation inside the CompareIC) could lead to
arbitrary memory access.
Short-term fix is to use the proper runtime functions (unified with the
interpreter now) for comparisons. Next task is to provide optimized
versions of these based on the CodeStubAssembler, which can then be used
via code stubs in TurboFan or directly in handlers in the interpreter.
R=mstarzinger@chromium.org
BUG=v8:4788
LOG=n
Review URL: https://codereview.chromium.org/1738153002
Cr-Commit-Position: refs/heads/master@{#34335}
Adds support for cpu profiler logging to the interpreter. Modifies the
the API to be passed AbstractCode objects instead of Code objects, and
adds extra functions to AbstractCode which is required by log.cc and
cpu-profiler.cc.
The main change in sampler.cc is to determine if a stack frame is an
interpreter stack frame, and if so, use the bytecode address as the pc
for that frame. This allows sampling of bytecode functions. This
requires adding support to SafeStackIterator to determine if a frame is
interpreted, which we do by checking the PC against pre-stored addresses
for the start and end of interpreter entry builtins.
Also removes CodeDeleteEvents which are dead code and haven't
been reported for some time.
Still to do is tracking source positions which will be done in a
followup CL.
BUG=v8:4766
LOG=N
Review URL: https://codereview.chromium.org/1728593002
Cr-Commit-Position: refs/heads/master@{#34321}
Reason for revert:
Speculative revert in attempt to fix#2 crasher on canary.
Original issue's description:
> [compiler] Drop the CompareNilIC.
>
> Since both null and undefined are also marked as undetectable now, we
> can just test that bit instead of having the CompareNilIC try to collect
> feedback to speed up the general case (without the undetectable bit
> being used).
>
> Drive-by-fix: Update the type system to match the new handling of
> undetectable in the runtime.
>
> R=danno@chromium.org
>
> Committed: https://crrev.com/666aec0348c8793e61c8633dee7ad29a514239ba
> Cr-Commit-Position: refs/heads/master@{#34237}
TBR=danno@chromium.org,verwaest@chromium.org,bmeurer@chromium.org
LOG=y
BUG=chromium:589897
NOTRY=true
Review URL: https://codereview.chromium.org/1743433002
Cr-Commit-Position: refs/heads/master@{#34308}
This adds explicit setters for the SharedFunctionInfo::function_data
field. Such setters are safer because they allow for explicit checking
of which values are allowed, and they improve readability because the
intended semantics become clear for each call-site. Also fix a cctest
case along the way.
R=rmcilroy@chromium.org
Review URL: https://codereview.chromium.org/1730853005
Cr-Commit-Position: refs/heads/master@{#34297}
Reason for revert:
Build failure on Linux64 arm64 ASAN:
http://build.chromium.org/p/client.v8/builders/V8%20Linux64%20ASAN%20arm64%20-%20debug%20builder/builds/4829
(Leaks memory, somehow.)
Original issue's description:
> Encode interpreter::SourcePositionTable as variable-length ints.
>
> This reduces the memory consumption of SourcePositionTable by ca. 2/3.
> Over Octane, this reduces the source position table memory consumption
> from ~370kB to ~115kB, which makes it ca. 10% of the total bytecode size
> (~1.1MB)
>
> BUG=
>
> Committed: https://crrev.com/a6f41f7b8226555c5900440f6e3092b3545ee0f6
> Cr-Commit-Position: refs/heads/master@{#34250}
TBR=jochen@chromium.org,rmcilroy@chromium.org,yangguo@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review URL: https://codereview.chromium.org/1728193003
Cr-Commit-Position: refs/heads/master@{#34251}
This reduces the memory consumption of SourcePositionTable by ca. 2/3.
Over Octane, this reduces the source position table memory consumption
from ~370kB to ~115kB, which makes it ca. 10% of the total bytecode size
(~1.1MB)
BUG=
Review URL: https://codereview.chromium.org/1704943002
Cr-Commit-Position: refs/heads/master@{#34250}
Since both null and undefined are also marked as undetectable now, we
can just test that bit instead of having the CompareNilIC try to collect
feedback to speed up the general case (without the undetectable bit
being used).
Drive-by-fix: Update the type system to match the new handling of
undetectable in the runtime.
R=danno@chromium.org
Review URL: https://codereview.chromium.org/1722193002
Cr-Commit-Position: refs/heads/master@{#34237}
For now WasmFrame doesn't summarize the wasm frames. That'll require adding the
metadata in wasm-compiler similar to DeoptimizationInputData.
Teach the basic backtrace to iterate over stack frames instead of JS frames.
Update the wasm stack test.
`git cl format` touches random lines in files I touch.
R=titzer@chromium.org
TEST=d8 --test --expose-wasm test/mjsunit/mjsunit.js test/mjsunit/wasm/stack.js
Originally landed in: https://codereview.chromium.org/1712003003/
Reverted in: https://codereview.chromium.org/1730673002/
This patch puts the JSFunction on the C++ stack.
Review URL: https://codereview.chromium.org/1724063002
Cr-Commit-Position: refs/heads/master@{#34225}
Reason for revert:
[Sheriff] Seems to break gcmole:
https://build.chromium.org/p/client.v8/builders/V8%20Linux/builds/8295
Original issue's description:
> Add WasmFrame, backtraces reflect wasm's presence
>
> For now WasmFrame doesn't summarize the wasm frames. That'll require adding the
> metadata in wasm-compiler similar to DeoptimizationInputData.
>
> Teach the basic backtrace to iterate over stack frames instead of JS frames.
>
> Update the wasm stack test.
>
> `git cl format` touches random lines in files I touch.
>
> R=titzer@chromium.org
> TEST=d8 --test --expose-wasm test/mjsunit/mjsunit.js test/mjsunit/wasm/stack.js
>
> Committed: https://crrev.com/aeca945786dcccad3efecfddbf2c07aefa524a56
> Cr-Commit-Position: refs/heads/master@{#34220}
TBR=titzer@chromium.org,mvstanton@chromium.org,mstarzinger@chromium.org,jfb@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1730673002
Cr-Commit-Position: refs/heads/master@{#34221}
For now WasmFrame doesn't summarize the wasm frames. That'll require adding the
metadata in wasm-compiler similar to DeoptimizationInputData.
Teach the basic backtrace to iterate over stack frames instead of JS frames.
Update the wasm stack test.
`git cl format` touches random lines in files I touch.
R=titzer@chromium.org
TEST=d8 --test --expose-wasm test/mjsunit/mjsunit.js test/mjsunit/wasm/stack.js
Review URL: https://codereview.chromium.org/1712003003
Cr-Commit-Position: refs/heads/master@{#34220}
Adds a profiling counter to each BytecodeArray object, and adds
code to Jump and Return bytecode handlers to update this
counter by the size of the jump or the distance from the return
to the start of the function. This is more accurate than fullcodegen's
approach since it takes forward jumps into account as well as back-edges.
Modifies RuntimeProfiler to track ticks for interpreted frames.
Currently we use the SharedFunctionInfo::profiler_ticks() instead
of adding another to tick field to avoid adding another field to
BytecodeArray since SharedFunctionInfo::profiler_ticks() is only
used by Crankshaft otherwise so we shouldn't need both for
BUG=v8:4689
LOG=N
Review URL: https://codereview.chromium.org/1707693003
Cr-Commit-Position: refs/heads/master@{#34166}
Various syntactic forms now cause functions to have names where they
didn't before. Per the upcoming changes to the toString spec, only
a name that was literally part of a function's expression or declaration
is meant to be reflected in toString. This also happens to be the same
set of names that V8 currently outputs (without the --harmony-function-name
flag).
This required distinguishing anonymous FunctionExpressions from other sorts
of function definitions (like methods and getters/setters) in the AST, parser,
and at runtime.
The patch also takes the opportunity to remove one more argument (and enum)
from FunctionLiteral, as well as adding a special factory method for the
case of a FunctionLiteral representing toplevel or eval'd code.
BUG=v8:4760
LOG=n
Review URL: https://codereview.chromium.org/1712833002
Cr-Commit-Position: refs/heads/master@{#34132}
I replaced the hidden string with hidden_properties_symbol, so we don't
need the extra hash-check anymore. This is slightly faster anyway.
BUG=
Review URL: https://codereview.chromium.org/1707653003
Cr-Commit-Position: refs/heads/master@{#34086}
This avoids having to read the context and call through from the inlined
path in the JSReceiver case.
BUG=
Review URL: https://codereview.chromium.org/1698463002
Cr-Commit-Position: refs/heads/master@{#33949}
Reason for revert:
No fix needed, original CL was perfectly fine!
Original issue's description:
> Revert of [interpreter] Correctly thread through catch prediction. (patchset #1 id:1 of https://codereview.chromium.org/1690973002/ )
>
> Reason for revert:
> Depends on the reverted https://codereview.chromium.org/1691723002
>
> Original issue's description:
> > [interpreter] Correctly thread through catch prediction.
> >
> > This change correctly sets the {CatchPrediction} field in exception
> > handler tables for bytecode and optimized code. It also adds tests
> > independent of promise handling for this prediction, to ensure all our
> > backends are in sync on their prediction.
> >
> > R=rmcilroy@chromium.org,yangguo@chromium.org
> > TEST=mjsunit/compiler/debug-catch-prediction
> > BUG=v8:4674
> > LOG=n
> >
> > Committed: https://crrev.com/ba55f5594cb0b4a1a1e9b35d87fe54afe2d93f3b
> > Cr-Commit-Position: refs/heads/master@{#33906}
>
> TBR=rmcilroy@chromium.org,yangguo@chromium.org,mstarzinger@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:4674
>
> Committed: https://crrev.com/c5229b311968fd638a6cd537c341b1055eb7be97
> Cr-Commit-Position: refs/heads/master@{#33922}
TBR=rmcilroy@chromium.org,yangguo@chromium.org,adamk@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4674
Review URL: https://codereview.chromium.org/1689113004
Cr-Commit-Position: refs/heads/master@{#33933}
Reason for revert:
Depends on the reverted https://codereview.chromium.org/1691723002
Original issue's description:
> [interpreter] Correctly thread through catch prediction.
>
> This change correctly sets the {CatchPrediction} field in exception
> handler tables for bytecode and optimized code. It also adds tests
> independent of promise handling for this prediction, to ensure all our
> backends are in sync on their prediction.
>
> R=rmcilroy@chromium.org,yangguo@chromium.org
> TEST=mjsunit/compiler/debug-catch-prediction
> BUG=v8:4674
> LOG=n
>
> Committed: https://crrev.com/ba55f5594cb0b4a1a1e9b35d87fe54afe2d93f3b
> Cr-Commit-Position: refs/heads/master@{#33906}
TBR=rmcilroy@chromium.org,yangguo@chromium.org,mstarzinger@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4674
Review URL: https://codereview.chromium.org/1695613002
Cr-Commit-Position: refs/heads/master@{#33922}
- Remove unused methods that we should never actually use like SetArea() or
set_size().
- Live bytes are now reported with --trace-live-bytes and not gc-verbose.
BUG=chromium:581076
LOG=N
Review URL: https://codereview.chromium.org/1686413002
Cr-Commit-Position: refs/heads/master@{#33908}
This change correctly sets the {CatchPrediction} field in exception
handler tables for bytecode and optimized code. It also adds tests
independent of promise handling for this prediction, to ensure all our
backends are in sync on their prediction.
R=rmcilroy@chromium.org,yangguo@chromium.org
TEST=mjsunit/compiler/debug-catch-prediction
BUG=v8:4674
LOG=n
Review URL: https://codereview.chromium.org/1690973002
Cr-Commit-Position: refs/heads/master@{#33906}
The break location heavily relies on relocation info. This change
abstracts that away. Currently there is only one implementation for
this interface, for JIT code. Future changes will introduce an
implementation to iterate bytecode arrays.
R=rmcilroy@chromium.org, vogelheim@chromium.org
BUG=v8:4690
LOG=N
Review URL: https://codereview.chromium.org/1682853003
Cr-Commit-Position: refs/heads/master@{#33869}
Preparing the young generation for (real) non-contiguous backing memory, this
change removes object masks that are used to compute containment in semi and new
space. The masks are replaced by lookups for object tags and page headers, where
possible.
Details:
- Use the fast checks (page header lookups) for containment in regular code.
- Use the slow version that masks out the page start adress and iterates all
pages of a space for debugging/verification.
- The slow version works for off-heap/unmapped memory.
- Encapsulate all checks for the old->new barrier in Heap::RecordWrite().
BUG=chromium:581412
LOG=N
Review URL: https://codereview.chromium.org/1632913003
Cr-Commit-Position: refs/heads/master@{#33857}
Previously, Object.values() and Object.entries() were piggy-backing on
Object.keys(). This meant that they would pre-filter non-enumerable properties,
violating the runtime behaviour of the methods. Unfortunately, this does not
match the current proposal text.
Also incorporates several tests verifying this behaviour based on tests included
in the ChakraCore implementation.
In this reland, the new patch fills up the longer-lasting FixedArray with
`undefined` to avoid the crash in Heap::Verify().
Originally reviewed at https://codereview.chromium.org/1637753004
BUG=v8:4663
LOG=N
R=adamk@chromium.org, rossberg@chromium.org, littledan@chromium.org
Review URL: https://codereview.chromium.org/1673673002
Cr-Commit-Position: refs/heads/master@{#33818}
Generally we only care whether the next object is a hidden prototype.
It's simpler to check whether the current object has a hidden prototype
instead of walking to the next prototype and checking its map.
BUG=
Review URL: https://codereview.chromium.org/1675223002
Cr-Commit-Position: refs/heads/master@{#33816}
It's fine to use JS_OBJECT_TYPE for JSIteratorResult and only have a
preallocated initial map for them to avoid unnecessary polymorphism
from generators / builtin iterators. The instance type doesn't
provide any advantage, since we always have to treat JSIteratorResult
objects as regular JSObjects later.
R=yangguo@chromium.orgTBR=hpayer@chromium.org
Review URL: https://codereview.chromium.org/1680513002
Cr-Commit-Position: refs/heads/master@{#33800}
Previously ObjectTemplate::New() logic relied on the fact that all the accessor properties are already installed in the initial map of the function object of the constructor FunctionTemplate.
When the FunctionTemplate were instantiated the accessors of the instance templates from the whole inheritance chain were accumulated and added to the initial map.
ObjectTemplate::SetSetAccessor() used to explicitly ensure that the ObjectTemplate has a constructor and therefore an initial map to add all accessors to.
The new approach is to add all the accessors and data properties to the object exactly when the ObjectTemplate is instantiated. In order to keep it fast we now cache the object boilerplates in the Isolate::template_instantiations_cache (the former function_cache), so the object creation turns to be a deep copying of the boilerplate object.
BUG=chromium:579009
LOG=Y
Committed: https://crrev.com/6a118774244d087b5979e9291d628a994f21d59d
Cr-Commit-Position: refs/heads/master@{#33674}
Review URL: https://codereview.chromium.org/1642223003
Cr-Commit-Position: refs/heads/master@{#33798}
Reason for revert:
[Sheriff] Breaks gc stress:
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20gc%20stress/builds/1642
Original issue's description:
> [es7] refactor and fix Object.values() / Object.entries()
>
> Previously, Object.values() and Object.entries() were piggy-backing on
> Object.keys(). This meant that they would pre-filter non-enumerable properties,
> violating the runtime behaviour of the methods. Unfortunately, this does not
> match the current proposal text.
>
> Also incorporates several tests verifying this behaviour based on tests included
> in the ChakraCore implementation.
>
> BUG=v8:4663
> LOG=N
> R=adamk@chromium.org, rossberg@chromium.org, littledan@chromium.org
>
> Committed: https://crrev.com/5c5ccd9d7f8693990d1a9eb26ba3a94f376dcf0b
> Cr-Commit-Position: refs/heads/master@{#33782}
TBR=littledan@chromium.org,adamk@chromium.org,cbruni@chromium.org,rossberg@chromium.org,caitpotter88@gmail.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4663
Review URL: https://codereview.chromium.org/1675663002
Cr-Commit-Position: refs/heads/master@{#33787}
Previously, Object.values() and Object.entries() were piggy-backing on
Object.keys(). This meant that they would pre-filter non-enumerable properties,
violating the runtime behaviour of the methods. Unfortunately, this does not
match the current proposal text.
Also incorporates several tests verifying this behaviour based on tests included
in the ChakraCore implementation.
BUG=v8:4663
LOG=N
R=adamk@chromium.org, rossberg@chromium.org, littledan@chromium.org
Review URL: https://codereview.chromium.org/1637753004
Cr-Commit-Position: refs/heads/master@{#33782}
This makes the field in question more generic by renaming it from the
previous "depth" to "data". Pure refactoring, no function change.
R=rmcilroy@chromium.org,yangguo@chromium.org
Review URL: https://codereview.chromium.org/1670983003
Cr-Commit-Position: refs/heads/master@{#33779}
Reason for revert:
Must revert for now due to chromium api natives issues.
Original issue's description:
> Type Feedback Vector lives in the closure
>
> (RELAND: the problem before was a missing write barrier for adding the code
> entry to the new closure. It's been addressed with a new macro instruction
> and test. The only change to this CL is the addition of two calls to
> __ RecordWriteCodeEntryField() in the platform CompileLazy builtin.)
>
> We get less "pollution" of type feedback if we have one vector per native
> context, rather than one for the whole system. This CL moves the vector
> appropriately.
>
> We rely more heavily on the Optimized Code Map in the SharedFunctionInfo. The
> vector actually lives in the first slot of the literals array (indeed there is
> great commonality between those arrays, they can be thought of as the same
> thing). So we make greater effort to ensure there is a valid literals array
> after compilation.
>
> This meant, for performance reasons, that we needed to extend
> FastNewClosureStub to support creating closures with literals. And ultimately,
> it drove us to move the optimized code map lookup out of FastNewClosureStub
> and into the compile lazy builtin.
>
> The heap change is trivial so I TBR Hannes for it...
> Also, Yang has had a look at the debugger changes already and approved 'em. So he is TBR style too.
> And Benedikt reviewed it as well.
>
> TBR=hpayer@chromium.org, yangguo@chromium.org, bmeurer@chromium.org
>
> BUG=
>
> Committed: https://crrev.com/bb31db3ad6de16f86a61f6c7bbfd3274e3d957b5
> Cr-Commit-Position: refs/heads/master@{#33741}
TBR=bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review URL: https://codereview.chromium.org/1670813005
Cr-Commit-Position: refs/heads/master@{#33766}
(RELAND: the problem before was a missing write barrier for adding the code
entry to the new closure. It's been addressed with a new macro instruction
and test. The only change to this CL is the addition of two calls to
__ RecordWriteCodeEntryField() in the platform CompileLazy builtin.)
We get less "pollution" of type feedback if we have one vector per native
context, rather than one for the whole system. This CL moves the vector
appropriately.
We rely more heavily on the Optimized Code Map in the SharedFunctionInfo. The
vector actually lives in the first slot of the literals array (indeed there is
great commonality between those arrays, they can be thought of as the same
thing). So we make greater effort to ensure there is a valid literals array
after compilation.
This meant, for performance reasons, that we needed to extend
FastNewClosureStub to support creating closures with literals. And ultimately,
it drove us to move the optimized code map lookup out of FastNewClosureStub
and into the compile lazy builtin.
The heap change is trivial so I TBR Hannes for it...
Also, Yang has had a look at the debugger changes already and approved 'em. So he is TBR style too.
And Benedikt reviewed it as well.
TBR=hpayer@chromium.org, yangguo@chromium.org, bmeurer@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1668103002
Cr-Commit-Position: refs/heads/master@{#33741}
This implements proper context switching while unwinding the stack due
to an exception being handled in interpreted code. The context under
which the handler is scoped is being preserved in a dedicated register
while the try-block is running. Both, the stack unwinding machinery as
well as the graph builder, restore the context from that register.
R=rmcilroy@chromium.org,bmeurer@chromium.org
BUG=v8:4674
LOG=n
Review URL: https://codereview.chromium.org/1665833002
Cr-Commit-Position: refs/heads/master@{#33733}
Reason for revert:
Fails a lot of layout tests and blocks the roll. Can be easily reproduced with a local Chromium checkout.
Reference: https://codereview.chromium.org/1652413003/
Original issue's description:
> [api] Make ObjectTemplate::SetNativeDataProperty() work even if the ObjectTemplate does not have a constructor.
>
> Previously ObjectTemplate::New() logic relied on the fact that all the accessor properties are already installed in the initial map of the function object of the constructor FunctionTemplate.
> When the FunctionTemplate were instantiated the accessors of the instance templates from the whole inheritance chain were accumulated and added to the initial map.
> ObjectTemplate::SetSetAccessor() used to explicitly ensure that the ObjectTemplate has a constructor and therefore an initial map to add all accessors to.
>
> The new approach is to add all the accessors and data properties to the object exactly when the ObjectTemplate is instantiated. In order to keep it fast we now cache the object boilerplates in the Isolate::template_instantiations_cache (the former function_cache), so the object creation turns to be a deep copying of the boilerplate object.
>
> This CL also prohibits non-primitive properties in ObjectTemplate to avoid potential cross-context leaks.
>
> BUG=chromium:579009
> LOG=Y
>
> Committed: https://crrev.com/6a118774244d087b5979e9291d628a994f21d59d
> Cr-Commit-Position: refs/heads/master@{#33674}
TBR=verwaest@chromium.org,ishell@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:579009
Review URL: https://codereview.chromium.org/1660263003
Cr-Commit-Position: refs/heads/master@{#33698}
