Don't take a fake UGI every time we execute Javascript.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 28a872ef78202b0087fa0a49be6249372d093734..9bc6e576abd66415e3bdd6afac77843a8f3f6563 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -1224,13 +1224,16 @@ void RenderFrameImpl::OnCSSInsertRequest(const std::string& css) {
 void RenderFrameImpl::OnJavaScriptExecuteRequest(
     const base::string16& jscript,
     int id,
-    bool notify_result) {
+    bool notify_result,
+    bool set_ugi_for_tests) {

[Rick Byers, 2014/08/29 13:38:38]

I'm a little nervous that it would be too easy for some non-test code to call
this accidentally without realizing the implications.  Can you split this into
two methods without too much code duplication?

Actually, I don't see any changes here that call this function passing true. 
Why do you need this at all?

[Zeeshan Qureshi, 2014/08/29 16:16:37]

This is the method that gets called when a JavascriptExecuteRequest IPC is
received, so the method setting this true is
RenderFrameHost::ExecuteJavascriptForTests(). This function doesn't get called
directly around here too, it's used via ExecuteJavascript().

To split this into 2 would require adding a new IPC.

[Rick Byers, 2014/08/29 16:21:44]

Ah, of course - sorry, that makes sense.  I was thinking this method was public.
 Since IPCs are almost never used directly I think sharing the IPC and splitting
into separate methods immediately above that is fine.

   TRACE_EVENT_INSTANT0("test_tracing", "OnJavaScriptExecuteRequest",
                        TRACE_EVENT_SCOPE_THREAD);
 
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
-  v8::Handle<v8::Value> result =
-      frame_->executeScriptAndReturnValue(WebScriptSource(jscript));
+  v8::Handle<v8::Value> result = set_ugi_for_tests ?
+    frame_->executeScriptAndReturnValueForTests(WebScriptSource(jscript)) :
+    frame_->executeScriptAndReturnValue(WebScriptSource(jscript));
+
   if (notify_result) {
     base::ListValue list;
     if (!result.IsEmpty()) {
@@ -1494,7 +1497,7 @@ void RenderFrameImpl::LoadURLExternally(blink::WebLocalFrame* frame,
 }
 
 void RenderFrameImpl::ExecuteJavaScript(const base::string16& javascript) {
-  OnJavaScriptExecuteRequest(javascript, 0, false);
+  OnJavaScriptExecuteRequest(javascript, 0, false, false);
 }
 
 ServiceRegistry* RenderFrameImpl::GetServiceRegistry() {