3 files changed, 17 insertions, 3 deletions
diff --git a/content/browser/tab_contents/background_contents.h b/content/browser/tab_contents/background_contents.h
index ef03cd4..e544fde 100644
--- a/content/browser/tab_contents/background_contents.h
+++ b/content/browser/tab_contents/background_contents.h
@@ -67,6 +67,7 @@ class BackgroundContents : public RenderViewHostDelegate,
   virtual void DidNavigate(RenderViewHost* render_view_host,
                            const ViewHostMsg_FrameNavigate_Params& params);
   virtual WebPreferences GetWebkitPrefs();
+  virtual void ProcessWebUIMessage(const ViewHostMsg_DomMessage_Params& params);
   virtual void RunJavaScriptMessage(const std::wstring& message,
                                     const std::wstring& default_prompt,
                                     const GURL& frame_url,
diff --git a/content/browser/tab_contents/tab_contents.cc b/content/browser/tab_contents/tab_contents.cc
index 408eb4b..6c72691 100644
--- a/content/browser/tab_contents/tab_contents.cc
+++ b/content/browser/tab_contents/tab_contents.cc
@@ -366,9 +366,6 @@ void TabContents::AddObservers() {
 }
 
 bool TabContents::OnMessageReceived(const IPC::Message& message) {
-  if (web_ui() && web_ui()->OnMessageReceived(message))
-    return true;
-
   ObserverListBase<TabContentsObserver>::Iterator it(observers_);
   TabContentsObserver* observer;
   while ((observer = it.GetNext()) != NULL)
@@ -2010,6 +2007,19 @@ void TabContents::DomOperationResponse(const std::string& json_string,
                                        int automation_id) {
 }
 
+void TabContents::ProcessWebUIMessage(
+    const ExtensionHostMsg_DomMessage_Params& params) {
+  if (!render_manager_.web_ui()) {
+    // This can happen if someone uses window.open() to open an extension URL
+    // from a non-extension context.
+    render_view_host()->Send(new ExtensionMsg_Response(
+        render_view_host()->routing_id(), params.request_id, false, "",
+        "Access to extension API denied."));
+    return;
+  }
+  render_manager_.web_ui()->ProcessWebUIMessage(params);
+}
+
 void TabContents::ProcessExternalHostMessage(const std::string& message,
                                              const std::string& origin,
                                              const std::string& target) {
diff --git a/content/browser/tab_contents/tab_contents.h b/content/browser/tab_contents/tab_contents.h
index f690393..17992dc 100644
--- a/content/browser/tab_contents/tab_contents.h
+++ b/content/browser/tab_contents/tab_contents.h
@@ -73,6 +73,7 @@ class TabContentsObserver;
 class TabContentsSSLHelper;
 class TabContentsView;
 class URLPattern;
+struct ExtensionHostMsg_DomMessage_Params;
 struct RendererPreferences;
 struct ThumbnailScore;
 struct ViewHostMsg_FrameNavigate_Params;
@@ -806,6 +807,8 @@ class TabContents : public PageNavigator,
                               WindowOpenDisposition disposition);
   virtual void DomOperationResponse(const std::string& json_string,
                                     int automation_id);
+  virtual void ProcessWebUIMessage(
+      const ExtensionHostMsg_DomMessage_Params& params);
   virtual void ProcessExternalHostMessage(const std::string& message,
                                           const std::string& origin,
                                           const std::string& target);