Remove always-true --harmony-string-trimming runtime flag

It was shipped in Chrome 66.

Bug: v8:6530, v8:8238
Change-Id: I07e95073ffcf388659b9d0b16a081e0f5a5eedaf
Reviewed-on: https://chromium-review.googlesource.com/1253603Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56323}

src/bootstrapper.cc

@@ -2089,10 +2089,23 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kStringPrototypeToString, 0, true);
     SimpleInstallFunction(isolate_, prototype, "trim",
                           Builtins::kStringPrototypeTrim, 0, false);
-    SimpleInstallFunction(isolate_, prototype, "trimLeft",
-                          Builtins::kStringPrototypeTrimStart, 0, false);
-    SimpleInstallFunction(isolate_, prototype, "trimRight",
-                          Builtins::kStringPrototypeTrimEnd, 0, false);
+
+    // Install `String.prototype.trimStart` with `trimLeft` alias.
+    Handle<JSFunction> trim_start_fun =
+        SimpleInstallFunction(isolate_, prototype, "trimStart",
+                              Builtins::kStringPrototypeTrimStart, 0, false);
+    JSObject::AddProperty(isolate_, prototype,
+                          factory->InternalizeUtf8String("trimLeft"),
+                          trim_start_fun, DONT_ENUM);
+
+    // Install `String.prototype.trimEnd` with `trimRight` alias.
+    Handle<JSFunction> trim_end_fun =
+        SimpleInstallFunction(isolate_, prototype, "trimEnd",
+                              Builtins::kStringPrototypeTrimEnd, 0, false);
+    JSObject::AddProperty(isolate_, prototype,
+                          factory->InternalizeUtf8String("trimRight"),
+                          trim_end_fun, DONT_ENUM);
+
     SimpleInstallFunction(isolate_, prototype, "toLocaleLowerCase",
                           Builtins::kStringPrototypeToLocaleLowerCase, 0,
                           false);
@@ -4418,40 +4431,6 @@ void Genesis::InitializeGlobal_harmony_sharedarraybuffer() {
   }
 }
 
-void Genesis::InitializeGlobal_harmony_string_trimming() {
-  if (!FLAG_harmony_string_trimming) return;
-
-  Handle<JSGlobalObject> global(native_context()->global_object(), isolate());
-  Factory* factory = isolate()->factory();
-
-  Handle<JSObject> string_prototype(
-      native_context()->initial_string_prototype(), isolate());
-
-  {
-    Handle<String> trim_left_name = factory->InternalizeUtf8String("trimLeft");
-    Handle<String> trim_start_name =
-        factory->InternalizeUtf8String("trimStart");
-    Handle<JSFunction> trim_left_fun = Handle<JSFunction>::cast(
-        JSObject::GetProperty(isolate_, string_prototype, trim_left_name)
-            .ToHandleChecked());
-    JSObject::AddProperty(isolate_, string_prototype, trim_start_name,
-                          trim_left_fun, DONT_ENUM);
-    trim_left_fun->shared()->SetName(*trim_start_name);
-  }
-
-  {
-    Handle<String> trim_right_name =
-        factory->InternalizeUtf8String("trimRight");
-    Handle<String> trim_end_name = factory->InternalizeUtf8String("trimEnd");
-    Handle<JSFunction> trim_right_fun = Handle<JSFunction>::cast(
-        JSObject::GetProperty(isolate_, string_prototype, trim_right_name)
-            .ToHandleChecked());
-    JSObject::AddProperty(isolate_, string_prototype, trim_end_name,
-                          trim_right_fun, DONT_ENUM);
-    trim_right_fun->shared()->SetName(*trim_end_name);
-  }
-}
-
 void Genesis::InitializeGlobal_harmony_array_prototype_values() {
   if (!FLAG_harmony_array_prototype_values) return;
   Handle<JSFunction> array_constructor(native_context()->array_function(),

src/flag-definitions.h

@@ -235,7 +235,6 @@ DEFINE_IMPLICATION(harmony_class_fields, harmony_private_fields)
 
 // Features that are shipping (turned on by default, but internal flag remains).
 #define HARMONY_SHIPPING_BASE(V)                                         \
-  V(harmony_string_trimming, "harmony String.prototype.trim{Start,End}") \
   V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")              \
   V(harmony_function_tostring, "harmony Function.prototype.toString")    \
   V(harmony_import_meta, "harmony import.meta property")                 \

test/mjsunit/string-trim.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-string-trimming
-
 assertEquals('trim',      String.prototype.trim.name);
 assertEquals('trimStart', String.prototype.trimStart.name);
 assertEquals('trimStart', String.prototype.trimLeft.name);

test/webkit/string-trim.js

@@ -21,8 +21,6 @@
 // (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-string-trimming
-
 description("This test checks the `trim`, `trimStart`/`trimLeft`, and `trimEnd`/`trimRight` methods on `String.prototype`.");
 
 // References to trim(), trimLeft() and trimRight() functions for testing Function's *.call() and *.apply() methods