Fixes ASan crash for an embedded Blink-in-JS component.

third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp

Index: third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp b/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
index 2ff20cce431400eaa32a5f3d61a254c5a24661ff..0b2194872f30271f74bbf3715b239414a3aadfcb 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
@@ -145,6 +145,9 @@ static void messageHandlerInMainThread(v8::Local<v8::Message> message, v8::Local
     ASSERT(isMainThread());
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
 
+    if (isolate->GetEnteredContext().IsEmpty())
+        return;
+
     // If called during context initialization, there will be no entered context.
     ScriptState* scriptState = ScriptState::current(isolate);
     if (!scriptState->contextIsValid())