Cancel prerenders for pages that call window.print()

chrome/browser/prerender/prerender_message_filter.h

Index: chrome/browser/prerender/prerender_message_filter.h
diff --git a/chrome/browser/prerender/prerender_message_filter.h b/chrome/browser/prerender/prerender_message_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..6c1190c1f898b7eb89c8c0245ff0596eb5932d32
--- /dev/null
+++ b/chrome/browser/prerender/prerender_message_filter.h
@@ -0,0 +1,42 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_PRERENDER_PRERENDER_MESSAGE_FILTER_H_
+#define CHROME_BROWSER_PRERENDER_PRERENDER_MESSAGE_FILTER_H_
+
+#include "content/browser/browser_message_filter.h"
+
+class BrowserRenderProcessHost;
+struct PrintHostMsg_ScriptedPrint_Params;
+struct PrintMsg_PrintPages_Params;
+
+namespace prerender {
+
+class PrerenderManager;
+
+class PrerenderMessageFilter : public BrowserMessageFilter {
+ public:
+  PrerenderMessageFilter(BrowserRenderProcessHost* browser_render_process_host,
+                         PrerenderManager* prerender_manager);
+
+  // BrowserMessageFilter methods.
+  virtual void OverrideThreadForMessage(const IPC::Message& message,
+                                        BrowserThread::ID* thread) OVERRIDE;
+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 bool* message_was_ok) OVERRIDE;
+ private:
+  virtual ~PrerenderMessageFilter() {}
+
+  void OnScriptedPrint(const PrintHostMsg_ScriptedPrint_Params& params,
+                       PrintMsg_PrintPages_Params* settings);
+
+  BrowserRenderProcessHost* browser_render_process_host_;
+  PrerenderManager* prerender_manager_;

[cbentzel, 2011/05/13 12:00:28]

This should be using a WeakPtr for the PrerenderManager, I think.

You may run into a corner-case race where a message is seen on IO thread and
forwarded to the UI thread. In the interim, the PrerenderManager is destroyed on
the UI thread. Stale memory is then accessed.

[dominich, 2011/05/13 15:05:33]

Done.

+
+//  DISALLOW_COPY_AND_ASSIGN(PrerenderMessageFilter);

[cbentzel, 2011/05/13 12:00:28]

Why is this commented out?

[dominich, 2011/05/13 15:05:33]

Done.

+};
+
+}
+
+#endif  // CHROME_BROWSER_PRERENDER_PRERENDER_MESSAGE_FILTER_H_