Remove --harmony-tostring runtime flag

ES2015 Object.prototype.toString semantics were enabled in version 4.9,
which has been in stable Chrome for nearly two weeks at this point.

R=littledan@chromium.org

Review URL: https://codereview.chromium.org/1784033002

Cr-Commit-Position: refs/heads/master@{#34732}

src/bootstrapper.cc

@@ -2251,7 +2251,6 @@ void Bootstrapper::ExportExperimentalFromRuntime(Isolate* isolate,
                           isolate->factory()->ToBoolean(FLAG), NONE); \
   }
 
-  INITIALIZE_FLAG(FLAG_harmony_tostring)
   INITIALIZE_FLAG(FLAG_harmony_species)
 
 #undef INITIALIZE_FLAG
@@ -2293,13 +2292,6 @@ void InstallPublicSymbol(Factory* factory, Handle<Context> native_context,
 }
 
 
-void Genesis::InitializeGlobal_harmony_tostring() {
-  if (!FLAG_harmony_tostring) return;
-  InstallPublicSymbol(factory(), native_context(), "toStringTag",
-                      factory()->to_string_tag_symbol());
-}
-
-
 void Genesis::InitializeGlobal_harmony_regexp_subclass() {
   if (!FLAG_harmony_regexp_subclass) return;
   InstallPublicSymbol(factory(), native_context(), "match",
@@ -2957,7 +2949,6 @@ bool Genesis::InstallExperimentalNatives() {
   static const char* harmony_modules_natives[] = {nullptr};
   static const char* harmony_regexps_natives[] = {"native harmony-regexp.js",
                                                   nullptr};
-  static const char* harmony_tostring_natives[] = {nullptr};
   static const char* harmony_iterator_close_natives[] = {nullptr};
   static const char* harmony_sloppy_natives[] = {nullptr};
   static const char* harmony_sloppy_function_natives[] = {nullptr};

src/flag-definitions.h

@@ -223,7 +223,6 @@ DEFINE_IMPLICATION(es_staging, harmony_tailcalls)
 #define HARMONY_SHIPPING(V)                                               \
   V(harmony_function_name, "harmony Function name inference")             \
   V(harmony_iterator_close, "harmony iterator finalization")              \
-  V(harmony_tostring, "harmony toString")                                 \
   V(harmony_regexps, "harmony regular expression extensions")             \
   V(harmony_unicode_regexps, "harmony unicode regexps")                   \
   V(harmony_sloppy, "harmony features in sloppy mode")                    \

src/js/messages.js

@@ -23,7 +23,6 @@ var callSitePositionSymbol =
     utils.ImportNow("call_site_position_symbol");
 var callSiteStrictSymbol =
     utils.ImportNow("call_site_strict_symbol");
-var FLAG_harmony_tostring;
 var Float32x4ToString;
 var formattedStackTraceSymbol =
     utils.ImportNow("formatted_stack_trace_symbol");
@@ -67,10 +66,6 @@ utils.Import(function(from) {
   Uint8x16ToString = from.Uint8x16ToString;
 });
 
-utils.ImportFromExperimental(function(from) {
-  FLAG_harmony_tostring = from.FLAG_harmony_tostring;
-});
-
 // -------------------------------------------------------------------
 
 var GlobalError;
@@ -87,13 +82,8 @@ function NoSideEffectsObjectToString() {
   if (IS_NULL(this)) return "[object Null]";
   var O = TO_OBJECT(this);
   var builtinTag = %_ClassOf(O);
-  var tag;
+  var tag = %GetDataProperty(O, toStringTagSymbol);
-  if (FLAG_harmony_tostring) {
+  if (!IS_STRING(tag)) {
-    tag = %GetDataProperty(O, toStringTagSymbol);
-    if (!IS_STRING(tag)) {
-      tag = builtinTag;
-    }
-  } else {
     tag = builtinTag;
   }
   return `[object ${tag}]`;

src/js/symbol.js

@@ -84,9 +84,7 @@ utils.InstallConstants(GlobalSymbol, [
   // "search", searchSymbol,
   // "split, splitSymbol,
   "toPrimitive", toPrimitiveSymbol,
-  // TODO(dslomov, caitp): Currently defined in harmony-tostring.js ---
+  "toStringTag", toStringTagSymbol,
-  // Move here when shipping
-  // "toStringTag", toStringTagSymbol,
   "unscopables", unscopablesSymbol,
 ]);
 

src/objects.cc

@@ -2463,11 +2463,9 @@ Handle<String> JSReceiver::GetConstructorName(Handle<JSReceiver> receiver) {
     }
   }
 
-  if (FLAG_harmony_tostring) {
+  Handle<Object> maybe_tag = JSReceiver::GetDataProperty(
-    Handle<Object> maybe_tag = JSReceiver::GetDataProperty(
+      receiver, isolate->factory()->to_string_tag_symbol());
-        receiver, isolate->factory()->to_string_tag_symbol());
+  if (maybe_tag->IsString()) return Handle<String>::cast(maybe_tag);
-    if (maybe_tag->IsString()) return Handle<String>::cast(maybe_tag);
-  }
 
   PrototypeIterator iter(isolate, receiver);
   if (iter.IsAtEnd()) return handle(receiver->class_name());
@@ -16647,16 +16645,14 @@ MaybeHandle<String> Object::ObjectProtoToString(Isolate* isolate,
       Object::ToObject(isolate, object).ToHandleChecked();
 
   Handle<String> tag;
-  if (FLAG_harmony_tostring) {
+  Handle<Object> to_string_tag;
-    Handle<Object> to_string_tag;
+  ASSIGN_RETURN_ON_EXCEPTION(
-    ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, to_string_tag,
-        isolate, to_string_tag,
+      JSReceiver::GetProperty(receiver,
-        JSReceiver::GetProperty(receiver,
+                              isolate->factory()->to_string_tag_symbol()),
-                                isolate->factory()->to_string_tag_symbol()),
+      String);
-        String);
+  if (to_string_tag->IsString()) {
-    if (to_string_tag->IsString()) {
+    tag = Handle<String>::cast(to_string_tag);
-      tag = Handle<String>::cast(to_string_tag);
-    }
   }
 
   if (tag.is_null()) {

test/cctest/test-api.cc

@@ -13300,8 +13300,6 @@ THREADED_TEST(ObjectProtoToString) {
 
 
 TEST(ObjectProtoToStringES6) {
-  // TODO(dslomov, caitp): merge into ObjectProtoToString test once shipped.
-  i::FLAG_harmony_tostring = true;
   LocalContext context;
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);
@@ -24759,7 +24757,6 @@ TEST(AccessCheckedIsConcatSpreadable) {
 
 
 TEST(AccessCheckedToStringTag) {
-  i::FLAG_harmony_tostring = true;
   v8::Isolate* isolate = CcTest::isolate();
   HandleScope scope(isolate);
   LocalContext env;

test/mjsunit/compare-known-objects-tostringtag.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --harmony-tostring
+// Flags: --allow-natives-syntax
 
 function le(a, b) {
   return a <= b;

test/mjsunit/es6/array-iterator.js

@@ -25,7 +25,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --allow-natives-syntax --harmony-tostring
+// Flags: --allow-natives-syntax
 
 
 var NONE = 0;

test/mjsunit/es6/array-tostring.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-tostring
-
 var global = this;
 
 var funs = {

test/mjsunit/es6/built-in-accessor-names.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-tostring
-
 'use strict';
 
 function assertGetterName(expected, object, name) {

test/mjsunit/es6/collection-iterator.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --harmony-tostring
+// Flags: --allow-natives-syntax
 
 
 (function TestSetIterator() {

test/mjsunit/es6/collections.js

@@ -25,7 +25,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --expose-gc --allow-natives-syntax --harmony-tostring
+// Flags: --expose-gc --allow-natives-syntax
 
 
 function assertSize(expected, collection) {

test/mjsunit/es6/generators-objects.js

@@ -25,7 +25,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --allow-natives-syntax --harmony-tostring
+// Flags: --allow-natives-syntax
 
 // Test instantations of generators.
 

test/mjsunit/es6/json.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-tostring
-
 function testJSONToString() {
   assertEquals('[object JSON]', "" + JSON);
   assertEquals("JSON", JSON[Symbol.toStringTag]);

test/mjsunit/es6/math.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-tostring
-
 function testMathToString() {
   assertEquals('[object Math]', "" + Math);
   assertEquals("Math", Math[Symbol.toStringTag]);

test/mjsunit/es6/object-tostring.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-tostring --harmony-proxies
+// Flags: --harmony-proxies
 
 var global = this;
 

test/mjsunit/es6/promises.js

@@ -25,7 +25,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --allow-natives-syntax --harmony-tostring --promise-extra
+// Flags: --allow-natives-syntax --promise-extra
 
 // Make sure we don't rely on functions patchable by monkeys.
 var call = Function.prototype.call.call.bind(Function.prototype.call)

test/mjsunit/es6/string-iterator.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-tostring
-
 function TestStringPrototypeIterator() {
   assertTrue(String.prototype.hasOwnProperty(Symbol.iterator));
   assertFalse("".hasOwnProperty(Symbol.iterator));

test/mjsunit/es6/symbols.js

@@ -25,7 +25,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --expose-gc --allow-natives-syntax --harmony-tostring
+// Flags: --expose-gc --allow-natives-syntax
 
 var symbols = []
 

test/mjsunit/es6/typedarray.js

@@ -25,8 +25,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --harmony-tostring
-
 // ArrayBuffer
 
 function TestByteLength(param, expectedByteLength) {

test/mjsunit/harmony/sharedarraybuffer.js

@@ -25,7 +25,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --harmony-sharedarraybuffer --harmony-tostring
+// Flags: --harmony-sharedarraybuffer
 
 
 // SharedArrayBuffer

test/mjsunit/harmony/simd.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-simd --harmony-tostring  --harmony-reflect
+// Flags: --harmony-simd --harmony-reflect
 // Flags: --allow-natives-syntax --expose-natives-as natives --noalways-opt
 
 function lanesForType(typeName) {