Move out DidStartProvisionalLoad from WebContentsImpl into Navigator.

content/browser/renderer_host/frame_tree_node.cc

Index: content/browser/renderer_host/frame_tree_node.cc
diff --git a/content/browser/renderer_host/frame_tree_node.cc b/content/browser/renderer_host/frame_tree_node.cc
index 81ea3619ef05b1ff1bcd2a0d4abb4e3e76f3d279..7d679ddad82c4e8d132361793a111ba93c8326d4 100644
--- a/content/browser/renderer_host/frame_tree_node.cc
+++ b/content/browser/renderer_host/frame_tree_node.cc
@@ -13,13 +13,15 @@ namespace content {
 
 const int64 FrameTreeNode::kInvalidFrameId = -1;
 
-FrameTreeNode::FrameTreeNode(int64 frame_id, const std::string& name,
+FrameTreeNode::FrameTreeNode(Navigator* navigator,
+                             int64 frame_id,
+                             const std::string& name,
                              scoped_ptr<RenderFrameHostImpl> render_frame_host)
-  : frame_id_(frame_id),
-    frame_name_(name),
-    owns_render_frame_host_(true),
-    render_frame_host_(render_frame_host.release()) {
-}
+    : frame_id_(frame_id),
+      frame_name_(name),
+      navigator_(navigator),
+      owns_render_frame_host_(true),
+      render_frame_host_(render_frame_host.release()) {}
 
 FrameTreeNode::~FrameTreeNode() {
   if (owns_render_frame_host_)