Refactor the loading tracking logic in WebContentsImpl.

content/browser/frame_host/frame_tree_node.h

Index: content/browser/frame_host/frame_tree_node.h
diff --git a/content/browser/frame_host/frame_tree_node.h b/content/browser/frame_host/frame_tree_node.h
index 5d0a34bd366fd3875a632891acc18ac624c64080..c896bb63a042a40f6d44d88afb69fbfb6ba3a5f7 100644
--- a/content/browser/frame_host/frame_tree_node.h
+++ b/content/browser/frame_host/frame_tree_node.h
@@ -112,6 +112,11 @@ class CONTENT_EXPORT FrameTreeNode {
     return is_loading_;
   }
 
+  void set_loading_progress(double loading_progress) {
+    loading_progress_ = loading_progress;
+  }
+  double get_loading_progress() const { return loading_progress_; }

[clamy, 2015/02/13 12:13:43]

s/get_loading_progress()/loading_progress()

nit: Add an empty line above.

[Fabrice (no longer in Chrome), 2015/02/13 18:04:24]

Done.

[clamy, 2015/02/16 14:20:59]

I don't see the modification to the accessor name in the new patch set (see the
style guide here:
http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Function_Names)

[Fabrice (no longer in Chrome), 2015/02/20 12:58:58]

Done.

+
   RenderFrameHostImpl* current_frame_host() const {
     return render_manager_.current_frame_host();
   }
@@ -167,6 +172,9 @@ class CONTENT_EXPORT FrameTreeNode {
   // RenderFrameHost or using a counter to balance the events out.
   bool is_loading_;

[carlosk, 2015/02/13 15:05:41]

Does the tracking of the loading progress happens in sync with the loading flag
being set? If so, is it possible to eliminate the |bool| value and track loading
only with the |double| (for instance is_loading() could be implemented as
|return loading_progress_ >= 1.0d|)? This would avoid inconsistent states
between them.

[Fabrice (no longer in Chrome), 2015/02/13 18:04:24]

This sounded good until I actually tried it and it caused crashes and what not.
Another issue is that it is possible that due to rounding errors, we set an
intermediate load progress to 1.0 while the content is not actually done
loading.

 
+  // Double value representing the frame's completion progress (from 0 to 1).
+  double loading_progress_;
+
   DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
 };