re-use WebUIs

this is a partial revert of r133077 and an alternative fix for bug 121741. The last commit was faulty because a same-document navigate would not send new DocumentAvailableInFrame IPCs, hence all WebUISend messages would be ignored after a same document navigation. An example of a same-document navigation is when the user presses back, and the page handles window.onpopstate.

The new fix:
Re-use WebUI objects for navigations where we re-use the render view, and the old and new URLs return the same WebUIController type. This covers both the reload case and the same-document nav case. This way, the re-used WebUI is still initialized and is able to continue to handle messages without the possibility of unexpected messages causing crashes. WebUI re-builds on every back/forward/reload are also wasteful so this is a performance win.

BUG=123705,121741,123710
TEST=

Review URL: http://codereview.chromium.org/10154004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@134055 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 3 insertions, 16 deletions

diff --git a/content/browser/webui/web_ui_impl.h b/content/browser/webui/web_ui_impl.h
index df245c7b..d0dfcab 100644
--- a/content/browser/webui/web_ui_impl.h
+++ b/content/browser/webui/web_ui_impl.h
@@ -7,9 +7,9 @@
 #pragma once
 
 #include <map>
-#include <set>
 
 #include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
 #include "content/public/browser/web_ui.h"
 #include "ipc/ipc_channel.h"
 
@@ -18,7 +18,8 @@ class RenderViewHost;
 }
 
 class CONTENT_EXPORT WebUIImpl : public content::WebUI,
-                                 public IPC::Channel::Listener {
+                                 public IPC::Channel::Listener,
+                                 public base::SupportsWeakPtr<WebUIImpl> {
  public:
   explicit WebUIImpl(content::WebContents* contents);
   virtual ~WebUIImpl();
@@ -28,15 +29,6 @@ class CONTENT_EXPORT WebUIImpl : public content::WebUI,
   // RenderViewHostManager will reuse RenderView instances.
   void RenderViewCreated(content::RenderViewHost* render_view_host);
 
-  // Called when the document element is available for the page. |main_frame|
-  // is true if the main frame's document is the one that's ready; otherwise
-  // the frame is an iframe and |source_url| gives its URL. The WebUI ignores
-  // messages until the document is available, because otherwise when we reuse
-  // a RenderView, we can receive and attempt to handle WebUISend messages from
-  // the prior navigation, which were in-flight when the RenderView got
-  // repurposed.
-  void DocumentAvailableInFrame(const GURL& source_url);
-
   // WebUI implementation:
   virtual content::WebContents* GetWebContents() const OVERRIDE;
   virtual content::WebUIController* GetController() const OVERRIDE;
@@ -119,11 +111,6 @@ class CONTENT_EXPORT WebUIImpl : public content::WebUI,
   // iframe).
   std::string frame_xpath_;
 
-  // List of URL origins in the renderer for which the document is ready. Each
-  // origin identifies a frame; two frames with the same origin may cause this
-  // to break.
-  std::set<GURL> document_available_origins_;
-
   scoped_ptr<content::WebUIController> controller_;
 
   DISALLOW_COPY_AND_ASSIGN(WebUIImpl);