Implement a fast buffer allocator for Vector, HashTable and StringBuilder

Source/bindings/core/v8/V8GCController.cpp

Index: Source/bindings/core/v8/V8GCController.cpp
diff --git a/Source/bindings/core/v8/V8GCController.cpp b/Source/bindings/core/v8/V8GCController.cpp
index 1f162db35d3b0c812f8b81c9b0f4574325e17140..fa543dae34142e5aef09464d31bda09891e07313 100644
--- a/Source/bindings/core/v8/V8GCController.cpp
+++ b/Source/bindings/core/v8/V8GCController.cpp
@@ -333,6 +333,7 @@ static unsigned long long usedHeapSize(v8::Isolate* isolate)
 
 void V8GCController::gcPrologue(v8::GCType type, v8::GCCallbackFlags flags)
 {
+    BufferAllocator::setIgnoreHitRateCount(true);
     // FIXME: It would be nice if the GC callbacks passed the Isolate directly....
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
     if (type == v8::kGCTypeScavenge)
@@ -382,6 +383,7 @@ void V8GCController::majorGCPrologue(v8::Isolate* isolate, bool constructRetaine
 
 void V8GCController::gcEpilogue(v8::GCType type, v8::GCCallbackFlags flags)
 {
+    BufferAllocator::setIgnoreHitRateCount(false);
     // v8::kGCCallbackFlagForced forces a Blink heap garbage collection
     // when a garbage collection was forced from V8. This is either used
     // for tests that force GCs from JavaScript to verify that objects die