Make breakpoints not crash sky

sky/engine/bindings/core/v8/V8Initializer.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 65 matching lines @@
     return 0;
 }
 
 static void reportFatalErrorInMainThread(const char* location, const char* message)
 {
     int memoryUsageMB = blink::Platform::current()->actualMemoryUsageMB();
     printf("V8 error: %s (%s).  Current memory usage: %d MB\n", message, location, memoryUsageMB);
     CRASH();
 }
 
+static LocalFrame* retrieveFrameWithGlobalObjectCheck(v8::Handle<v8::Context> context)
+{
+    if (context.IsEmpty())
+        return 0;
+
+    // FIXME: This is a temporary hack for crbug.com/345014.
+    // Currently it's possible that V8 can trigger Debugger::ProcessDebugEvent for a context
+    // that is being initialized (i.e., inside Context::New() of the context).
+    // We should fix the V8 side so that it won't trigger the event for a half-baked context
+    // because there is no way in the embedder side to check if the context is half-baked or not.
+    if (isMainThread() && DOMWrapperWorld::windowIsBeingInitialized())
+        return 0;
+
+    v8::Handle<v8::Value> global = V8Window::findInstanceInPrototypeChain(context->Global(), context->GetIsolate());
+    if (global.IsEmpty())
+        return 0;
+
+    return toFrameIfNotDetached(context);

[abarth-chromium, 2014/11/19 02:05:40]

If you're the only client of this function, you can simplify it a bit.  You
don't need to check isMainThread and you don't need to call toFrameIfNotDetached
because you're just interested in the bool result.

+}
+
 static void messageHandlerInMainThread(v8::Handle<v8::Message> message, v8::Handle<v8::Value> data)
 {
     ASSERT(isMainThread());
     // It's possible that messageHandlerInMainThread() is invoked while we're initializing a window.
     // In that half-baked situation, we don't have a valid context nor a valid world,
     // so just return immediately.
     if (DOMWrapperWorld::windowIsBeingInitialized())
         return;
 
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
+    // Check if we're in the V8DebugContext which does not have a window object.
+    if (!retrieveFrameWithGlobalObjectCheck(isolate->GetCurrentContext())) {
+        printf("Unhandled: %s %s\n",
+            toCoreString(message->Get()).ascii().data(),
+            toCoreString(message->GetSourceLine()).ascii().data());
+        return;
+    }
     // If called during context initialization, there will be no entered window.
     LocalDOMWindow* enteredWindow = enteredDOMWindow(isolate);
     if (!enteredWindow)
         return;
 
     String errorMessage = toCoreString(message->Get());
 
     v8::Handle<v8::StackTrace> stackTrace = message->GetStackTrace();
     RefPtr<ScriptCallStack> callStack = nullptr;
     int scriptId = message->GetScriptOrigin().ScriptID()->Value();
@@ skipping 86 matching lines @@
     v8::V8::SetFatalErrorHandler(reportFatalErrorInMainThread);
     v8::V8::AddMessageListener(messageHandlerInMainThread);
     v8::V8::SetFailedAccessCheckCallbackFunction(failedAccessCheckCallbackInMainThread);
 
     isolate->SetEventLogger(timerTraceProfilerInMainThread);
 
     ScriptProfiler::initialize();
 }
 
 } // namespace blink