bindings: Use Maybe version of v8::String::NewFromUtf8()

Source/bindings/core/v8/V8Binding.h

Index: Source/bindings/core/v8/V8Binding.h
diff --git a/Source/bindings/core/v8/V8Binding.h b/Source/bindings/core/v8/V8Binding.h
index 6e4b772d205aaba6b7fc31c45792855d8aa71d17..5118d741034f2545b91dddeeeee01b46e29b261d 100644
--- a/Source/bindings/core/v8/V8Binding.h
+++ b/Source/bindings/core/v8/V8Binding.h
@@ -347,16 +347,22 @@ inline v8::Handle<v8::String> v8String(v8::Isolate* isolate, const String& strin
     return V8PerIsolateData::from(isolate)->stringCache()->v8ExternalString(string.impl(), isolate);
 }
 
-inline v8::Handle<v8::String> v8AtomicString(v8::Isolate* isolate, const char* str)

[bashi, 2015/03/20 08:16:44]

I think we can remove this. When length is -1, v8::String::NewFromUtf8() calls
StringLength(), which should be the same as calling strlen().

+inline v8::Local<v8::String> v8NormalString(v8::Isolate* isolate, const char* str, int length = -1)
 {
     ASSERT(isolate);
-    return v8::String::NewFromUtf8(isolate, str, v8::String::kInternalizedString, strlen(str));
+    v8::Local<v8::String> value;
+    if (LIKELY(v8::String::NewFromUtf8(isolate, str, v8::NewStringType::kNormal, length).ToLocal(&value)))

[bashi, 2015/03/20 08:16:44]

I added LIKELY() because according to the v8.h, NewFromUtf8() only fails when
|length| is too long. But this might be unnecessary.

[haraken, 2015/03/20 09:46:08]

v8NormalString is performance-sensitive, so LIKELY would make sense. Rather I'm
a bit concerned that this CL might regress performance of some micro benchmarks.
Let's land this and see the perf bots.

+        return value;
+    return v8::String::Empty(isolate);
 }
 
-inline v8::Handle<v8::String> v8AtomicString(v8::Isolate* isolate, const char* str, size_t length)
+inline v8::Handle<v8::String> v8AtomicString(v8::Isolate* isolate, const char* str, int length = -1)
 {
     ASSERT(isolate);
-    return v8::String::NewFromUtf8(isolate, str, v8::String::kInternalizedString, length);
+    v8::Local<v8::String> value;
+    if (LIKELY(v8::String::NewFromUtf8(isolate, str, v8::NewStringType::kInternalized, length).ToLocal(&value)))
+        return value;
+    return v8::String::Empty(isolate);
 }
 
 inline v8::Handle<v8::Value> v8Undefined()