Properly find Frame from Node context

or debug callback can't get the listener.
Fix nwjs/nw.js#719

#0  WebCore::InspectorDebuggerAgent::didPause (this=0x7ffff7ee8800,
    scriptState=0x192e07eebb10, callFrames=..., exception=...)
    at ../../third_party/WebKit/Source/core/inspector/InspectorDebuggerAgent.cpp:682
#1  0x0000000003665f7e in WebCore::ScriptDebugServer::breakProgram (
    this=0x7ffff7ee8260, executionState=..., exception=...)
    at ../../third_party/WebKit/Source/bindings/v8/ScriptDebugServer.cpp:425
nwjs#2  0x0000000003666ceb in WebCore::ScriptDebugServer::handleV8DebugEvent (
    this=0x7ffff7ee8260, eventDetails=...)
    at ../../third_party/WebKit/Source/bindings/v8/ScriptDebugServer.cpp:503
nwjs#3  0x0000000003666012 in WebCore::ScriptDebugServer::v8DebugEventCallback (
    eventDetails=...)
    at ../../third_party/WebKit/Source/bindings/v8/ScriptDebugServer.cpp:435
nwjs#4  0x0000000000f7ecb3 in v8::internal::Debugger::CallCEventCallback (
    this=0x7ffff7eec520, event=v8::Break, exec_state=..., event_data=...,
    client_data=0x0) at ../../v8/src/debug.cc:2953
nwjs#5  0x0000000000f7ebf9 in v8::internal::Debugger::CallEventCallback (
    this=0x7ffff7eec520, event=v8::Break, exec_state=..., event_data=...,
    client_data=0x0) at ../../v8/src/debug.cc:2932
nwjs#6  0x0000000000f7eabd in v8::internal::Debugger::ProcessDebugEvent (
    this=0x7ffff7eec520, event=v8::Break, event_data=..., auto_continue=false)
    at ../../v8/src/debug.cc:2909
nwjs#7  0x0000000000f7e24d in v8::internal::Debugger::OnDebugBreak (
    this=0x7ffff7eec520, break_points_hit=..., auto_continue=false)
    at ../../v8/src/debug.cc:2750
nwjs#8  0x0000000000f7836f in v8::internal::Debug::Break (this=0x7ffff7eecc20,
    args=...) at ../../v8/src/debug.cc:992
nwjs#9  0x0000000000f787a8 in v8::internal::__RT_impl_Debug_Break (args=...,
    isolate=0x7ffff7e80020) at ../../v8/src/debug.cc:1062
nwjs#10 0x0000000000f78769 in v8::internal::Debug_Break (args_length=0,
    args_object=0x7fffffff8248, isolate=0x7ffff7e80020)
    at ../../v8/src/debug.cc:1061

Source/bindings/v8/PageScriptDebugServer.cpp

@@ -51,6 +51,25 @@
 
 namespace WebCore {
 
+static Frame* retrieveFrameWithNodeContext(v8::Handle<v8::Context> context)
+{
+  v8::HandleScope handle_scope;
+
+  v8::Context::Scope context_scope(node::g_context);
+  v8::Handle<v8::Object> global = node::g_context->Global();
+  v8::Local<v8::Value> val_window = global->Get(v8::String::New("window"));
+  if (val_window->IsUndefined())
+    return 0;
+  v8::Local<v8::Object> window = v8::Local<v8::Object>::Cast(val_window);
+  global = window->FindInstanceInPrototypeChain(V8DOMWindow::GetTemplate(context->GetIsolate(), worldTypeInMainThread(context->GetIsolate())));
+  if (global.IsEmpty())
+    return 0;
+  DOMWindow* win = V8DOMWindow::toNative(global);
+  if (!win)
+    return 0;
+  return win->frame();
+}
+
 static Frame* retrieveFrameWithGlobalObjectCheck(v8::Handle<v8::Context> context)
 {
     if (context.IsEmpty())
@@ -59,25 +78,12 @@ static Frame* retrieveFrameWithGlobalObjectCheck(v8::Handle<v8::Context> context
     v8::HandleScope handle_scope;
     // Test that context has associated global dom window object.
     v8::Handle<v8::Object> global = context->Global();
-    if (global.IsEmpty()) {
-        v8::Context::Scope context_scope(node::g_context);
-        global = node::g_context->Global();
-        v8::Local<v8::Value> val_window = global->Get(v8::String::New("window"));
-        if (val_window->IsUndefined())
-            return 0;
-        v8::Local<v8::Object> window = v8::Local<v8::Object>::Cast(val_window);
-        global = window->FindInstanceInPrototypeChain(V8DOMWindow::GetTemplate(context->GetIsolate(), worldTypeInMainThread(context->GetIsolate())));
-        if (global.IsEmpty())
-            return 0;
-        DOMWindow* win = V8DOMWindow::toNative(global);
-        if (!win)
-            return 0;
-        return win->frame();
-    }
+    if (global.IsEmpty())
+      return retrieveFrameWithNodeContext(context);
 
     global = global->FindInstanceInPrototypeChain(V8DOMWindow::GetTemplate(context->GetIsolate(), worldTypeInMainThread(context->GetIsolate())));
     if (global.IsEmpty())
-        return 0;
+      return retrieveFrameWithNodeContext(context);
 
     return toFrameIfNotDetached(context);
 }