PlzNavigate: stop navigations when opening a document for write

content/renderer/render_frame_impl.h

Index: content/renderer/render_frame_impl.h
diff --git a/content/renderer/render_frame_impl.h b/content/renderer/render_frame_impl.h
index 171d03f3c80d5c240b175dc25c259bcba1374631..9dd4557e1f444100d900bc55f3b3308ec8334972 100644
--- a/content/renderer/render_frame_impl.h
+++ b/content/renderer/render_frame_impl.h
@@ -590,6 +590,7 @@ class CONTENT_EXPORT RenderFrameImpl
   void didChangeThemeColor() override;
   void dispatchLoad() override;
   blink::WebEffectiveConnectionType getEffectiveConnectionType() override;
+  void abortClientNavigation() override;
   void didChangeSelection(bool is_empty_selection) override;
   bool handleCurrentKeyboardEvent() override;
   blink::WebColorChooser* createColorChooser(
@@ -896,6 +897,7 @@ class CONTENT_EXPORT RenderFrameImpl
                           const RequestNavigationParams& request_params,
                           bool has_stale_copy_in_cache,
                           int error_code);
+  void OnDroppedNavigation(int navigation_id);
   void OnGetSavableResourceLinks();
   void OnGetSerializedHtmlWithLocalLinks(
       const std::map<GURL, base::FilePath>& url_to_local_path,
@@ -1424,6 +1426,10 @@ class CONTENT_EXPORT RenderFrameImpl
   // is used and released in didStartProvisionalLoad().
   std::unique_ptr<PendingNavigationInfo> pending_navigation_info_;
 
+  // PlzNavigate
+  // An id to identify the last navigation sent to the browser.
+  int navigation_id_ = 0;

[nasko, 2017/03/16 21:23:14]

I'd like to hear what Charlie thinks about this approach. We used to have
page_id, which we removed and this kinda feels like this.

nit: unsigned?

[clamy, 2017/03/17 15:19:11]

TBH I'm not super happy about introducing an id, but I don't really see a better
way. The only thing is that it's absolutely not used on the browser side, and is
really meant for book keeping in the renderer process. When we switch to mojo, I
hope that with the services we can have a more reliable way of knowing that the
request we asked the browser to do was cancelled, and this id can go away.

For making the int unsigned, I'm going to transmit it as an int (given that -1
is a possible value), and I'd rather avoid the unsigned/signed conversion if
possible.

+
   base::WeakPtrFactory<RenderFrameImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameImpl);