Move out DidStartProvisionalLoad from WebContentsImpl into Navigator.

content/browser/frame_host/frame_tree.h

Index: content/browser/frame_host/frame_tree.h
diff --git a/content/browser/frame_host/frame_tree.h b/content/browser/frame_host/frame_tree.h
index f9bf80970a618366509b7bb7e70efffa8da544a1..88e3ee806bf819bdabf2ce5b099e9ad7706cecef 100644
--- a/content/browser/frame_host/frame_tree.h
+++ b/content/browser/frame_host/frame_tree.h
@@ -15,6 +15,8 @@
 namespace content {
 
 class FrameTreeNode;
+class NavigationControllerImpl;
+class NavigatorDelegate;
 class RenderProcessHost;
 class RenderViewHostImpl;
 
@@ -38,6 +40,13 @@ class CONTENT_EXPORT FrameTree {
   FrameTree();
   ~FrameTree();
 
+  // Initializes the frame tree with a NavigationController which keeps

[Charlie Reis, 2013/11/07 01:22:43]

If I understand correctly, InterstitialPages are going to have a FrameTree and a
Navigator that doesn't allow navigation after the first page commits.  I suppose
they still need a NavigationController to let them commit their first
navigation?

+  // session history for it and NavigationObserver which dispatches

[Charlie Reis, 2013/11/07 01:22:43]

nit: NavigatorDelegate.

+  // notifications for navigation events.
+  void Init(
+      NavigationControllerImpl* navigation_controller,

[Charlie Reis, 2013/11/07 01:22:43]

nit: Should go on previous line.

+      NavigatorDelegate* navigator_delegate);
+
   // Returns the FrameTreeNode with the given |frame_id|.
   FrameTreeNode* FindByID(int64 frame_id);
 
@@ -85,14 +94,22 @@ class CONTENT_EXPORT FrameTree {
 
   FrameTreeNode* GetRootForTesting() { return root_.get(); }
 
+  Navigator* navigator() {

[Charlie Reis, 2013/11/07 01:22:43]

Do we need this here?  I'm thinking we'll want to expose the root FrameTreeNode
for several reasons (e.g., from my RFHM CL).

+    return root_->navigator();
+  }
+
  private:
-  scoped_ptr<FrameTreeNode> CreateNode(int64 frame_id,
+  scoped_ptr<FrameTreeNode> CreateNode(Navigator* parent_navigator,
+                                       int64 frame_id,
                                        const std::string& frame_name,
                                        int render_frame_host_id,
                                        RenderProcessHost* render_process_host);
 
+  // The root node for the frame tree.
   scoped_ptr<FrameTreeNode> root_;
 
+  // Callback which is invoked when a FrameTreeNode is removed from the
+  // tree.
   base::Callback<void(RenderViewHostImpl*, int64)> on_frame_removed_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameTree);