Move load progress tracking logic to the frame tree.

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 458887baaf6403ba538c8775fadf7fbf695e1ba6..6f333613d86efb013be93e03cd0447f162f080f2 100644
--- a/content/browser/frame_host/frame_tree_node.h
+++ b/content/browser/frame_host/frame_tree_node.h
@@ -30,6 +30,13 @@ class RenderFrameHostImpl;
 // are frame-specific (as opposed to page-specific).
 class CONTENT_EXPORT FrameTreeNode {
  public:
+  // These values indicate the loading progress status. The minimum progress
+  // value matches what Blink's ProgressTracker has traditionally used for a
+  // minimum progress value.

[nasko, 2015/03/24 17:26:11]

nit: I still think we can hide those to be private/anonymous values in follow-up
CLs, so a TODO for that might be useful to have.

[Fabrice (no longer in Chrome), 2015/03/25 17:35:01]

The issue is that right now, we need to access these values from FrameTree and I
do not think that is going to change.

[nasko, 2015/03/25 22:48:03]

It can be hidden from FrameTree, as it will not need to tell FTN anything. Once
we move the IPC to be handled by RFH, it will be telling FTN about its status.
This will be more clear once we do that work though.

[Fabrice (no longer in Chrome), 2015/03/26 11:05:24]

I'm readding the TODO, we'll see if we can remove it after moving the IPCs.

+  static const double kLoadingProgressNotStarted;
+  static const double kLoadingProgressMinimum;
+  static const double kLoadingProgressDone;
+
   // Returns the FrameTreeNode with the given global |frame_tree_node_id|,
   // regardless of which FrameTree it is in.
   static FrameTreeNode* GloballyFindByID(int64 frame_tree_node_id);
@@ -122,11 +129,16 @@ class CONTENT_EXPORT FrameTreeNode {
 
   bool IsDescendantOf(FrameTreeNode* other) const;
 
-  // Returns true if this frame is in a loading state.
+  // Returns true if this node is in a loading state.
   bool IsLoading() const;
 
-  // Returns the loading progress of this frame.
-  double GetLoadingProgress() const;
+  // Sets this node's loading progress (from 0 to 1).
+  void set_loading_progress(double loading_progress) {
+    loading_progress_ = loading_progress;
+  }
+
+  // Returns this node's loading progress.
+  double loading_progress() const { return loading_progress_; }
 
  private:
   void set_parent(FrameTreeNode* parent) { parent_ = parent; }
@@ -178,6 +190,9 @@ class CONTENT_EXPORT FrameTreeNode {
   // flags when a navigation for this frame commits.
   SandboxFlags effective_sandbox_flags_;
 
+  // Used to track this node's loading progress (from 0 to 1).
+  double loading_progress_;
+
   DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
 };