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

Source/bindings/core/v8/V8Binding.h

 /*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * Copyright (C) 2012 Ericsson AB. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
@@ skipping 329 matching lines @@
 // Return a V8 external string that shares the underlying buffer with the given
 // WebCore string. The reference counting mechanism is used to keep the
 // underlying buffer alive while the string is still live in the V8 engine.
 inline v8::Handle<v8::String> v8String(v8::Isolate* isolate, const String& string)
 {
     if (string.isNull())
         return v8::String::Empty(isolate);
     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()
 {
     return v8::Handle<v8::Value>();
 }
 
 // Conversion flags, used in toIntXX/toUIntXX.
 enum IntegerConversionConfiguration {
     NormalConversion,
@@ skipping 597 matching lines @@
 PassRefPtr<TraceEvent::ConvertableToTraceFormat> devToolsTraceEventData(v8::Isolate*, ExecutionContext*, v8::Handle<v8::Function>);
 
 // Callback functions used by generated code.
 void v8ConstructorAttributeGetter(v8::Local<v8::Name> propertyName, const v8::PropertyCallbackInfo<v8::Value>&);
 
 typedef void (*InstallTemplateFunction)(v8::Local<v8::FunctionTemplate>, v8::Isolate*);
 
 } // namespace blink
 
 #endif // V8Binding_h