Add UMA stats for predicted process counts with out-of-process iframes.

content/browser/web_contents/frame_tree_node.h

Index: content/browser/web_contents/frame_tree_node.h
diff --git a/content/browser/web_contents/frame_tree_node.h b/content/browser/web_contents/frame_tree_node.h
index c35df025929b7385788c64818d21ca14a24e8834..5bd3f1b135011aa56d71bb4541ae1187380d3954 100644
--- a/content/browser/web_contents/frame_tree_node.h
+++ b/content/browser/web_contents/frame_tree_node.h
@@ -10,6 +10,7 @@
 
 #include "base/basictypes.h"
 #include "content/common/content_export.h"
+#include "googleurl/src/gurl.h"
 
 namespace content {
 
@@ -42,6 +43,14 @@ class CONTENT_EXPORT FrameTreeNode {
     return children_[index];
   }
 
+  const GURL& current_url() const {
+    return current_url_;
+  }
+
+  void set_current_url(const GURL& url) {
+    current_url_ = url;
+  }
+
  private:
   // The unique identifier for the frame in the page.
   int64 frame_id_;
@@ -53,6 +62,12 @@ class CONTENT_EXPORT FrameTreeNode {
   // The immediate children of this specific frame.
   std::vector<FrameTreeNode*> children_;
 
+  // Track the current frame's last committed URL, so we can estimate the
+  // process impact of out-of-process iframes.
+  // TODO(creis): Remove this when we can store subframe URLs in the
+  // NavigationController.
+  GURL current_url_;
+
   DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
 };