Commit Graph

406 Commits

Author SHA1 Message Date
bmeurer
cb9b801069 [builtins] Make Math.max and Math.min fast by default.
The previous versions of Math.max and Math.min made it difficult to
optimize those (that's why we already have custom code in Crankshaft),
and due to lack of ideas what to do about the variable number of
arguments, we will probably need to stick in special code in TurboFan
as well; so inlining those builtins is off the table, hence there's no
real advantage in having them around as "not quite JS" with extra work
necessary in the optimizing compilers to still make those builtins
somewhat fast in cases where we cannot inline them (also there's a
tricky deopt loop in Crankshaft related to Math.min and Math.max, but
that will be dealt with later).

So to sum up: Instead of trying to make Math.max and Math.min semi-fast
in the optimizing compilers with weird work-arounds support %_Arguments
%_ArgumentsLength, we do provide the optimal code as native builtins
instead and call it a day (which gives a nice performance boost on some
benchmarks).

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1641083003

Cr-Commit-Position: refs/heads/master@{#33582}
2016-01-28 13:07:09 +00:00
mstarzinger
8bfa1ea33a [interpreter] Translate exception handlers into graph.
This translates the exception handler table attached to a bytecode array
correctly into exceptional projections within the TurboFan graph. We
perform an abstract simulation of handlers that are being entered and
exited by the bytecode iteration to track the correct handler for each
node.

R=oth@chromium.org
BUG=v8:4674
LOG=n

Review URL: https://codereview.chromium.org/1641723002

Cr-Commit-Position: refs/heads/master@{#33580}
2016-01-28 12:18:24 +00:00
mvstanton
a702785156 Revert of Type Feedback Vector lives in the closure (patchset #2 id:20001 of https://codereview.chromium.org/1642613002/ )
Reason for revert:
Bug: failing to use write barrier when writing code entry into closure.

Original issue's description:
> Reland of Type Feedback Vector lives in the closure
>
> (Fixed a bug found by nosnap builds.)
>
> 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...
>
> TBR=hpayer@chromium.org
> BUG=
>
> Committed: https://crrev.com/d984b3b0ce91e55800f5323b4bb32a06f8a5aab1
> Cr-Commit-Position: refs/heads/master@{#33548}

TBR=bmeurer@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/1643533003

Cr-Commit-Position: refs/heads/master@{#33556}
2016-01-27 15:05:38 +00:00
mvstanton
d984b3b0ce Reland of Type Feedback Vector lives in the closure
(Fixed a bug found by nosnap builds.)

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...

TBR=hpayer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1642613002

Cr-Commit-Position: refs/heads/master@{#33548}
2016-01-27 12:53:42 +00:00
mstarzinger
e3014ad848 [interpreter] Fix BytecodeGraphBuilder for disabled deopt.
This ensures that the BytecodeGraphBuilder can generate correct graphs
even when deoptimization has not been enabled. This configuration is not
enabled in production, and we might eventually decide to deprecate it
for good. Until then, this is a quick fix.

R=jarin@chromium.org
TEST=cctest/test-pipeline

Review URL: https://codereview.chromium.org/1640683002

Cr-Commit-Position: refs/heads/master@{#33545}
2016-01-27 12:08:27 +00:00
mvstanton
e2e7dc32ef Revert of Type Feedback Vector lives in the closure (patchset #12 id:260001 of https://codereview.chromium.org/1563213002/ )
Reason for revert:
FAilure on win32 bot, need to investigate webkit failures.

Original issue's description:
> Type Feedback Vector lives in the closure
>
> 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...
>
> TBR=hpayer@chromium.org
>
> BUG=
>
> Committed: https://crrev.com/a5200f7ed4d11c6b882fa667da7a1864226544b4
> Cr-Commit-Position: refs/heads/master@{#33518}

TBR=bmeurer@chromium.org,akos.palfi@imgtec.com
# 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/1632993003

Cr-Commit-Position: refs/heads/master@{#33520}
2016-01-26 15:02:29 +00:00
mvstanton
a5200f7ed4 Type Feedback Vector lives in the closure
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...

TBR=hpayer@chromium.org

BUG=

Review URL: https://codereview.chromium.org/1563213002

Cr-Commit-Position: refs/heads/master@{#33518}
2016-01-26 14:21:08 +00:00
mstarzinger
fd5505ca15 [interpreter] Fix how 'throw' is translated to TurboFan.
This fixes the translation of 'throw' bytecodes to TurboFan graphs. The
correct runtime function is being used now, also the frame states are
attached to the correct nodes now.

R=mythria@chromium.org
TEST=cctest/test-run-jsexceptions/ThrowMessageIndirectly
BUG=v8:4674
LOG=n

Review URL: https://codereview.chromium.org/1636033002

Cr-Commit-Position: refs/heads/master@{#33513}
2016-01-26 13:23:44 +00:00
rmcilroy
befe61fa3e [Interpreter] Add native function literal support.
Adds support for calling native function literals. Moves the logic for building
the native function's SharedFunctionInfo out of full-codegen into compiler.cc
to allow it to be shared between fullcodegen and Ignition.

BUG=v8:4686
LOG=N

Review URL: https://codereview.chromium.org/1635553002

Cr-Commit-Position: refs/heads/master@{#33510}
2016-01-26 11:30:46 +00:00
mstarzinger
b707ca4b54 [interpreter] Deprecate --ignition-fallback-on-catch flag.
The current support for try-catch in the interpreter can handle most of
the cases appearing in our test suite. Also the flag in question did not
detect try-finally constructs. This removes the flag and instead extends
the test expectations.

R=rmcilroy@chromium.org
BUG=v8:4674
LOG=n

Review URL: https://codereview.chromium.org/1631593003

Cr-Commit-Position: refs/heads/master@{#33494}
2016-01-25 15:57:51 +00:00
rmcilroy
9602f4b2d2 [Interpreter] Remove skips which have been fixed with Exceptions and For...Of.
BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1627943003

Cr-Commit-Position: refs/heads/master@{#33489}
2016-01-25 12:23:38 +00:00
mstarzinger
00b0a53685 [interpreter] Re-enable some tests that pass by now.
These tests have been disabled while support for try-finally was work in
progress. By now control flow is connected properly and the tests pass.

R=oth@chromium.org
BUG=v8:4674
LOG=n

Review URL: https://codereview.chromium.org/1626503002

Cr-Commit-Position: refs/heads/master@{#33474}
2016-01-22 17:11:17 +00:00
mstarzinger
0b3066b8f5 [interpreter] First implementation of stack unwinding.
This implements a first prototype of stack unwinding for interpreted
frames. The unwinding machinery performs a range-based lookup in the
given handler table and potentially continues dispatching at the handler
offset. Note that this does not yet correctly restore the context to the
correct value when the handler is being entered.

R=rmcilroy@chromium.org,oth@chromium.org
BUG=v8:4674
LOG=n

Review URL: https://codereview.chromium.org/1605633003

Cr-Commit-Position: refs/heads/master@{#33414}
2016-01-20 18:10:40 +00:00
ivica.bogosavljevic
e68ffc767d Add cctest/test-run-wasm-js/Run_JSSelect_0...6 to skip list for big-endian
Newly added tests cctest/test-run-wasm-js/Run_JSSelect_0...6 cause failures
on MIPS bigendian and are skipped until a solution is found.

BUG=

Review URL: https://codereview.chromium.org/1608813003

Cr-Commit-Position: refs/heads/master@{#33387}
2016-01-19 15:42:58 +00:00
rmcilroy
43c02e49d8 [Interpreter] Change ignition fallback flag to only fallback on catch, not eval.
Now that we support eval in Ignition, remove the fallback for eval checks
and make the flag only fallback on catch blocks.

BUG=v8:4280,v8:4676
LOG=N

Review URL: https://codereview.chromium.org/1595223004

Cr-Commit-Position: refs/heads/master@{#33384}
2016-01-19 11:33:50 +00:00
rmcilroy
609e754193 [Interpreter] Skip test-heap/Regress538257 on Arm64 Ignition due to flake.
BUG=v8:4280
LOG=N
TBR=machenbach@chromium.org
NOTRY=TRUE

Review URL: https://codereview.chromium.org/1584343006

Cr-Commit-Position: refs/heads/master@{#33337}
2016-01-15 16:04:56 +00:00
rmcilroy
be2210bcc4 [Interpreter] Remove Ignition skips fixed by 48a3227b
Remove ignition skips which are fixed by 48a3227b7d.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1590513003

Cr-Commit-Position: refs/heads/master@{#33322}
2016-01-15 11:26:24 +00:00
mbrandy
04f1759522 Skip failing wasm tests on platforms with function descriptors.
Temporarily disable until solution is implemented.

R=titzer@chromium.org, bradnelson@chromium.org, ahaas@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1581103005

Cr-Commit-Position: refs/heads/master@{#33308}
2016-01-14 17:57:40 +00:00
mbrandy
0c1430ac2b Additional 64-bit Wasm tests to skip list for big-endian.
R=titzer@chromium.org, hablich@chromium.org, paul.lind@imgtec.com
BUG=

Review URL: https://codereview.chromium.org/1582143004

Cr-Commit-Position: refs/heads/master@{#33306}
2016-01-14 17:28:04 +00:00
neis
96ec06efb0 Reland of "[Proxies] Ship Proxies + Reflect."
Failing chromium layout tests were marked for rebaselining.

Addition to original CL (https://codereview.chromium.org/1580693002/):
Skip some more ignition tests.

BUG=v8:3931,v8:1543
LOG=Y
R=hablich@chromium.org
CC=verwaest@chromium.org, rossberg@chromium.org,rmcilroy, oth

Review URL: https://codereview.chromium.org/1580783002

Cr-Commit-Position: refs/heads/master@{#33244}
2016-01-12 17:19:52 +00:00
rmcilroy
9b52c52845 [Interpreter] Add StackCheck node to BytecodeGraphBuilder graphs.
This fixes a number of crashes where other code was assuming there would
be at least one deopt point in all optimized functions (i.e., the
StackCheck) but we weren't producing any.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1572333002

Cr-Commit-Position: refs/heads/master@{#33243}
2016-01-12 17:08:27 +00:00
paul.lind
37b4f2879e Add Wasm tests to skip list for big-endian.
Get the BE bots green in the short term.

BUG=

Review URL: https://codereview.chromium.org/1571243002

Cr-Commit-Position: refs/heads/master@{#33197}
2016-01-11 10:19:17 +00:00
bmeurer
61f157370d [test] Remove obsolete entries from cctest status file.
R=danno@chromium.org

Review URL: https://codereview.chromium.org/1555823002

Cr-Commit-Position: refs/heads/master@{#33156}
2016-01-07 14:15:07 +00:00
rmcilroy
af95a4dd3e [Interpreter] Add Ignition whitelist for cctests.
Adds an ignition whitelist for cctests.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1557893002

Cr-Commit-Position: refs/heads/master@{#33096}
2016-01-04 21:01:34 +00:00
bmeurer
84a88a1bd0 [turbofan] Port Crankshaft's weak objects mechanism to TurboFan.
Use the same mechanism that is already available for Crankshaft to not
leak all kinds of things in TurboFan generated code. Long-term we will
support weakness in a better way, but for now, just use the
infrastructure that is already in place to avoid memory leaks via
TurboFan generated code.

R=jarin@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/1555743003

Cr-Commit-Position: refs/heads/master@{#33073}
2016-01-04 07:12:35 +00:00
Michael Hablich
df7fe6af21 [Test] Mark flaky test cctest/test-lockers/LockAndUnlockDifferentIsolates for real
BUG=v8:4642
LOG=N
NOTRY=true
TBR=machenbach@chromium.org,mvstanton@chromium.org

Review URL: https://codereview.chromium.org/1549663004 .

Cr-Commit-Position: refs/heads/master@{#33025}
2015-12-23 12:31:50 +00:00
hablich
2cea136a87 [Test] Mark flaky test cctest/test-lockers/LockAndUnlockDifferentIsolates
BUG=v8:4642
LOG=N
NOTRY=true
R=machenbach@chromium.org,mvstanton@chromium.org

Review URL: https://codereview.chromium.org/1542253002

Cr-Commit-Position: refs/heads/master@{#33021}
2015-12-23 10:03:18 +00:00
Hannes Payer
9a5650ac9e Remove obsolete PrototypeTransitionClearing cctest.
BUG=

Review URL: https://codereview.chromium.org/1520793003 .

Cr-Commit-Position: refs/heads/master@{#32795}
2015-12-11 12:53:09 +00:00
Ben L. Titzer
69cf31f0b7 Disable test-heap/PrototypeTransitionClearing
R=hpayer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1521583003 .

Cr-Commit-Position: refs/heads/master@{#32792}
2015-12-11 12:21:09 +00:00
machenbach
8452a75315 [test] Skip flaky test.
BUG=v8:4358
LOG=n
TBR=yangguo@chromium.org, hablich@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1475053002

Cr-Commit-Position: refs/heads/master@{#32282}
2015-11-25 15:23:49 +00:00
machenbach
87177738ce [test] Skip flaky test for turbofan on windows.
BUG=v8:4573
LOG=n
TBR=mstarzinger@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1465193006

Cr-Commit-Position: refs/heads/master@{#32276}
2015-11-25 14:23:08 +00:00
yangguo
436103e077 Skip test-heap/TestSizeOfRegExpCode on mips64.
R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/1448803003

Cr-Commit-Position: refs/heads/master@{#32008}
2015-11-16 14:36:32 +00:00
mbrandy
f83b8a61cf Skip test-run-machops/RunComputedCodeObject on AIX and PPC64BE.
This test, as written, is invalid on platforms which use function
descriptors.

See https://codereview.chromium.org/1377423002/ for background.

R=mstarzinger@chromium.org, titzer@chromium.org, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1438803002

Cr-Commit-Position: refs/heads/master@{#31967}
2015-11-12 19:10:32 +00:00
chunyang.dai
5736eb0ccb X87: Change the test case for X87 float operations
The CL https://codereview.chromium.org/1409013004 added / changed some test cases.
       Some new test cases use CheckFloatEq(...) and CheckDoubleEq(...) function for result
       check. When GCC compiling the CheckFloatEq() and CheckDoubleEq() function, those inlined
       functions has different behavior comparing with GCC ia32 build and x87 build. The major
       difference is sse float register still has single precision rounding semantic. While X87
       register has no such rounding precsion semantic when directly use register value. The V8
       turbofan JITTed has exactly same result in both X87 and IA32 port.

       So we add the following sentence to do type case to keep the same precision.
          float expect = *i * *j; // *i + *j, etc.

       For test case "RunFloat64MulAndFloat64Add1 / RunFloat64MulAndFloat64Add2 / RunFloat64MulAndFloat64Sub1
       / RunFloat64MulAndFloat64Sub2", the expected result calcaulated by GCC has difference precsion
       when comparing with V8 turbofan result for X87 platform. (Turbofan X87 result is the same as
       IA32 GCC and IA32 Turbofan). So we have to disable those four cases for X87 port.

BUG=

Review URL: https://codereview.chromium.org/1430943002

Cr-Commit-Position: refs/heads/master@{#31808}
2015-11-05 00:15:30 +00:00
bmeurer
30aca03ad1 [turbofan] Implement the call protocol properly for direct calls.
The callees are expected to properly set the number of actual
arguments passed to the callee, which is now represented correctly
in the TurboFan graphs by a new Parameter right before the context
Parameter.  Currently this is only being used for outgoing calls.

Note that this requires disabling two of the TF code stub tests,
because of the JavaScript graphs are not automagically compatible
with abitrary (incoming) code stub interface descriptors.  If we
want to support JS code stubs at all, then we need to find a sane
way to feed in this information.

Drive-by-fix: Don't insert a direct call to a classConstructor.

R=mstarzinger@chromium.org
BUG=v8:4413, v8:4428
LOG=n

Review URL: https://codereview.chromium.org/1410633006

Cr-Commit-Position: refs/heads/master@{#31789}
2015-11-04 14:08:59 +00:00
chunyang.dai
5978b926c6 For some platform such as X87, Crankshaft and Turbofan needs to use different
register configurations currently. This CL provides a mechanism so that
    optimizing compilers can select different Register Configuration.

BUG=

Review URL: https://codereview.chromium.org/1405673003

Cr-Commit-Position: refs/heads/master@{#31476}
2015-10-22 13:24:49 +00:00
mstarzinger
32ab65e9ea [turbofan] Re-enable debugger tests that no longer fail.
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1420543002

Cr-Commit-Position: refs/heads/master@{#31420}
2015-10-20 15:32:20 +00:00
bmeurer
58befc9b81 [test] Differentiate between exhaustive and default testing variants.
Review URL: https://codereview.chromium.org/1402353006

Cr-Commit-Position: refs/heads/master@{#31409}
2015-10-20 13:16:51 +00:00
Benedikt Meurer
063e2316d7 Revert "[turbofan] Stage --turbo-inlining behind --turbo flag." and "[turbofan] Skip more tests that fail with --turbo-inlining."
This reverts commit 019f9408dc,
6ed05f44af and
e34c343d2a.

TBR=mstarzinger@chromium.org
BUG=v8:4493
LOG=n

Review URL: https://codereview.chromium.org/1413183004 .

Cr-Commit-Position: refs/heads/master@{#31393}
2015-10-20 06:23:02 +00:00
mstarzinger
e34c343d2a [turbofan] Stage --turbo-inlining behind --turbo flag.
This stages the general purpose inlining mechanism in TurboFan and also
disables the remaining tests that still fail. We do this to get test
coverage early and to avoid regressing inlining as we go along.

R=bmeurer@chromium.org
BUG=v8:4493
LOG=n

Review URL: https://codereview.chromium.org/1412703002

Cr-Commit-Position: refs/heads/master@{#31386}
2015-10-20 03:54:12 +00:00
machenbach
366dc81143 [Swarming] Presort tests - slowest first.
Swarming won't support an incremental data file. By just
sorting the lowest hanging fruits to the beginning we
already get a big bang for the buck (>80% of the improvement
we get otherwise).

This will require semi-regular manual updates of the
slowest tests.

BUG=chromium:535160
LOG=n

Review URL: https://codereview.chromium.org/1385443002

Cr-Commit-Position: refs/heads/master@{#31061}
2015-10-01 19:19:17 +00:00
dusan.m.milosavljevic
8bd431de92 MIPS64: Add big-endian support for mips64.
TEST=
BUG=

Review URL: https://codereview.chromium.org/1334793004

Cr-Commit-Position: refs/heads/master@{#31011}
2015-09-29 17:23:55 +00:00
mlippautz
277795e28f [heap,cctest] Fix CodeRange tests that use AllocateRawMemory directly.
* Enforce invariants on the way.
* Unmark flaky CodeRange test.

BUG=v8:4141
BUG=v8:3005
LOG=N

Review URL: https://codereview.chromium.org/1325853003

Cr-Commit-Position: refs/heads/master@{#30524}
2015-09-01 18:39:32 +00:00
Hannes Payer
9a3327adad Don't explicitly tear down code range in cctest/test-alloc/CodeRange to avoid double-free.
BUG=v8:4141
LOG=n
R=mlippautz@chromium.org

Review URL: https://codereview.chromium.org/1312213007 .

Cr-Commit-Position: refs/heads/master@{#30371}
2015-08-26 09:28:37 +00:00
machenbach
53fbbf0296 [Sheriff] Mark test as flaky.
BUG=v8:4141
LOG=n
NOTRY=true
TBR=yangguo@chromium.org, vogelheim@chromium.org

Review URL: https://codereview.chromium.org/1263033005

Cr-Commit-Position: refs/heads/master@{#29972}
2015-08-03 11:42:10 +00:00
mvstanton
04a7123ae8 Bugfix: CCTest test-func-name-inference/InConstructor is broken
BUG=v8:4331
LOG=N

Review URL: https://codereview.chromium.org/1263763002

Cr-Commit-Position: refs/heads/master@{#29927}
2015-07-30 10:43:16 +00:00
yangguo
67efca8be6 Add test for referring function name for classes.
R=mvstanton@chromium.org
BUG=v8:4333
LOG=N

Review URL: https://codereview.chromium.org/1264603002

Cr-Commit-Position: refs/heads/master@{#29922}
2015-07-30 09:21:20 +00:00
yangguo
a67f31c48c Speed up cctest/test-debug/DebugBreakLoop.
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/1262613002

Cr-Commit-Position: refs/heads/master@{#29918}
2015-07-30 09:11:46 +00:00
mvstanton
d2e815f15b Bugfix: Incorrect type feedback vector structure on recompile.
Scoping rules are different on recompile vis-a-vis global loads.

BUG=chromium:514526
LOG=y
NOTREECHECKS=true

Review URL: https://codereview.chromium.org/1256413005

Cr-Commit-Position: refs/heads/master@{#29896}
2015-07-28 14:03:10 +00:00
machenbach
d12e3232e9 [test] Skip slow test in novfp3 mode.
TBR=yangguo@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1264443002

Cr-Commit-Position: refs/heads/master@{#29894}
2015-07-28 09:54:14 +00:00