Only create chromeHidden object when needed.

chrome/renderer/extensions/chrome_v8_context.h

Index: chrome/renderer/extensions/chrome_v8_context.h
diff --git a/chrome/renderer/extensions/chrome_v8_context.h b/chrome/renderer/extensions/chrome_v8_context.h
index dfa922db9fe9317f3304fee7f618cd15cc2dbb8c..bbacfd194b6d5d5e81a32302cd443522e64f1881 100644
--- a/chrome/renderer/extensions/chrome_v8_context.h
+++ b/chrome/renderer/extensions/chrome_v8_context.h
@@ -46,6 +46,18 @@ class ChromeV8Context {
     web_frame_ = NULL;
   }
 
+  // Returns a special Chrome-specific hidden object that is associated with a
+  // context, but not reachable from the JavaScript in that context. This is
+  // used by our v8::Extension implementations as a way to share code and as a
+  // bridge between C++ and JavaScript.
+  static v8::Handle<v8::Value> GetOrCreateChromeHidden(
+      v8::Handle<v8::Context> context);
+
+  // Return the chromeHidden object associated with this context, or an empty
+  // handle if no chrome hidden has been created (by GetOrCreateChromeHidden)
+  // yet for this context.
+  v8::Handle<v8::Value> GetChromeHidden() const;
+
   // Returns the RenderView associated with this context. Can return NULL if the
   // context is in the process of being destroyed.
   content::RenderView* GetRenderView() const;