Create a frame tree in WebContents on the browser side.

This is a small delta from the original patch at https://codereview.chromium.org/14374002/.

BUG=235879

Review URL: https://chromiumcodereview.appspot.com/14580004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@199087 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 355 insertions, 9 deletions

diff --git a/content/browser/renderer_host/frame_tree_node.cc b/content/browser/renderer_host/frame_tree_node.cc
new file mode 100644
index 0000000..3486a2d
--- /dev/null
+++ b/content/browser/renderer_host/frame_tree_node.cc
@@ -0,0 +1,40 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/renderer_host/frame_tree_node.h"
+
+#include <queue>
+
+#include "base/stl_util.h"
+
+namespace content {
+
+FrameTreeNode::FrameTreeNode(int64 frame_id, const std::string& name)
+  : frame_id_(frame_id),
+    frame_name_(name) {
+}
+
+FrameTreeNode::~FrameTreeNode() {
+  STLDeleteContainerPointers(children_.begin(), children_.end());
+}
+
+void FrameTreeNode::AddChild(FrameTreeNode* child) {
+  children_.push_back(child);
+}
+
+void FrameTreeNode::RemoveChild(int64 child_id) {
+  std::vector<FrameTreeNode*>::iterator iter;
+
+  for (iter = children_.begin(); iter != children_.end(); ++iter) {
+    if ((*iter)->frame_id() == child_id)
+      break;
+  }
+
+  if (iter != children_.end()) {
+    delete *iter;
+    children_.erase(iter);
+  }
+}
+
+}  // namespace content
diff --git a/content/browser/renderer_host/frame_tree_node.h b/content/browser/renderer_host/frame_tree_node.h
new file mode 100644
index 0000000..e35f409
--- /dev/null
+++ b/content/browser/renderer_host/frame_tree_node.h
@@ -0,0 +1,61 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_FRAME_TREE_NODE_H_
+#define CONTENT_BROWSER_RENDERER_HOST_FRAME_TREE_NODE_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+// Any page that contains iframes has a tree structure of the frames in the
+// renderer process. We are mirroring this tree in the browser process. This
+// class represents a node in this tree and is a wrapper for all objects that
+// are frame-specific (as opposed to page-specific).
+class CONTENT_EXPORT FrameTreeNode {
+ public:
+  FrameTreeNode(int64 frame_id, const std::string& name);
+  ~FrameTreeNode();
+
+  // This method takes ownership of the child pointer.
+  void AddChild(FrameTreeNode* child);
+  void RemoveChild(int64 child_id);
+
+  int64 frame_id() const {
+    return frame_id_;
+  }
+
+  const std::string& frame_name() const {
+    return frame_name_;
+  }
+
+  size_t child_count() const {
+    return children_.size();
+  }
+
+  FrameTreeNode* child_at(size_t index) const {
+    return children_[index];
+  }
+
+ private:
+  // The unique identifier for the frame in the page.
+  int64 frame_id_;
+
+  // The assigned name of the frame. This name can be empty, unlike the unique
+  // name generated internally in the DOM tree.
+  std::string frame_name_;
+
+  // The immediate children of this specific frame.
+  std::vector<FrameTreeNode*> children_;
+
+  DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_FRAME_TREE_NODE_H_
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index d3363f5..322cf35 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -171,6 +171,7 @@ RenderViewHostImpl::RenderViewHostImpl(
       suspended_nav_params_(NULL),
       is_swapped_out_(swapped_out),
       is_subframe_(false),
+      main_frame_id_(-1),
       run_modal_reply_msg_(NULL),
       run_modal_opener_id_(MSG_ROUTING_NONE),
       is_waiting_for_beforeunload_ack_(false),
@@ -1116,6 +1117,7 @@ void RenderViewHostImpl::OnRenderViewGone(int status, int exit_code) {
 
   // Reset state.
   ClearPowerSaveBlockers();
+  main_frame_id_ = -1;
 
   // Our base class RenderWidgetHost needs to reset some stuff.
   RendererExited(render_view_termination_status_, exit_code);
@@ -1186,6 +1188,18 @@ void RenderViewHostImpl::OnNavigate(const IPC::Message& msg) {
   if (is_waiting_for_unload_ack_)
     return;
 
+  // Cache the main frame id, so we can use it for creating the frame tree
+  // root node when needed.
+  if (PageTransitionIsMainFrame(validated_params.transition)) {
+    if (main_frame_id_ == -1) {
+      main_frame_id_ = validated_params.frame_id;
+    } else {
+      // TODO(nasko): We plan to remove the usage of frame_id in navigation
+      // and move to routing ids. This is in place to ensure that a
+      // renderer is not misbehaving and sending us incorrect data.
+      DCHECK_EQ(main_frame_id_, validated_params.frame_id);
+    }
+  }
   RenderProcessHost* process = GetProcess();
 
   // If the --site-per-process flag is passed, then the renderer process is
diff --git a/content/browser/renderer_host/render_view_host_impl.h b/content/browser/renderer_host/render_view_host_impl.h
index a03ba43..516af7e7 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -395,6 +395,10 @@ class CONTENT_EXPORT RenderViewHostImpl
     is_subframe_ = is_subframe;
   }
 
+  int64 main_frame_id() const {
+    return main_frame_id_;
+  }
+
   // Set the opener to null in the renderer process.
   void DisownOpener();
 
@@ -607,6 +611,11 @@ class CONTENT_EXPORT RenderViewHostImpl
   // different process from its parent page.
   bool is_subframe_;
 
+  // The frame id of the main (top level) frame. This value is set on the
+  // initial navigation of a RenderView and reset when the RenderView is
+  // terminated (in RenderViewGone).
+  int64 main_frame_id_;
+
   // If we were asked to RunModal, then this will hold the reply_msg that we
   // must return to the renderer to unblock it.
   IPC::Message* run_modal_reply_msg_;
diff --git a/content/browser/renderer_host/test_render_view_host.cc b/content/browser/renderer_host/test_render_view_host.cc
index 6f5310f..a84f4dc 100644
--- a/content/browser/renderer_host/test_render_view_host.cc
+++ b/content/browser/renderer_host/test_render_view_host.cc
@@ -35,6 +35,9 @@ SessionStorageNamespaceImpl* CreateSessionStorageNamespace(
   return new SessionStorageNamespaceImpl(
       static_cast<DOMStorageContextImpl*>(dom_storage_context));
 }
+
+const int64 kFrameId = 13UL;
+
 }  // namespace
 
 
@@ -248,6 +251,8 @@ TestRenderViewHost::TestRenderViewHost(
   // deleted in the destructor below, because
   // TestRenderWidgetHostView::Destroy() doesn't |delete this|.
   SetView(new TestRenderWidgetHostView(this));
+
+  main_frame_id_ = kFrameId;
 }
 
 TestRenderViewHost::~TestRenderViewHost() {
@@ -287,7 +292,7 @@ void TestRenderViewHost::SendNavigateWithTransition(
 
 void TestRenderViewHost::SendNavigateWithOriginalRequestURL(
     int page_id, const GURL& url, const GURL& original_request_url) {
-  OnDidStartProvisionalLoadForFrame(0, -1, true, url);
+  OnDidStartProvisionalLoadForFrame(kFrameId, -1, true, url);
   SendNavigateWithParameters(page_id, url, PAGE_TRANSITION_LINK,
                              original_request_url, 200, 0);
 }
@@ -301,7 +306,7 @@ void TestRenderViewHost::SendNavigateWithFile(
 void TestRenderViewHost::SendNavigateWithTransitionAndResponseCode(
     int page_id, const GURL& url, PageTransition transition,
     int response_code) {
-  OnDidStartProvisionalLoadForFrame(0, -1, true, url);
+  OnDidStartProvisionalLoadForFrame(kFrameId, -1, true, url);
   SendNavigateWithParameters(page_id, url, transition, url, response_code, 0);
 }
 
@@ -311,7 +316,7 @@ void TestRenderViewHost::SendNavigateWithParameters(
     const base::FilePath* file_path_for_history_item) {
   ViewHostMsg_FrameNavigate_Params params;
   params.page_id = page_id;
-  params.frame_id = 0;
+  params.frame_id = kFrameId;
   params.url = url;
   params.referrer = Referrer();
   params.transition = transition;
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 43ec8e5..66cd29e 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -692,6 +692,7 @@ bool WebContentsImpl::OnMessageReceived(RenderViewHost* render_view_host,
     IPC_MESSAGE_HANDLER(ViewHostMsg_OpenDateTimeDialog,
                         OnOpenDateTimeDialog)
 #endif
+    IPC_MESSAGE_HANDLER(ViewHostMsg_FrameAttached, OnFrameAttached)
     IPC_MESSAGE_HANDLER(ViewHostMsg_FrameDetached, OnFrameDetached)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
@@ -2425,9 +2426,45 @@ void WebContentsImpl::OnUpdateFaviconURL(
                     DidUpdateFaviconURL(page_id, candidates));
 }
 
-void WebContentsImpl::OnFrameDetached(int64 frame_id) {
+FrameTreeNode* WebContentsImpl::FindFrameTreeNodeByID(int64 frame_id) {
+  FrameTreeNode* node = NULL;
+  std::queue<FrameTreeNode*> queue;
+  queue.push(frame_tree_root_.get());
+
+  while (!queue.empty()) {
+    node = queue.front();
+    queue.pop();
+    if (node->frame_id() == frame_id)
+      return node;
+
+    for (size_t i = 0; i < node->child_count(); ++i)
+      queue.push(node->child_at(i));
+  }
+
+  return NULL;
+}
+
+void WebContentsImpl::OnFrameAttached(
+    int64 parent_frame_id,
+    int64 frame_id,
+    const std::string& frame_name) {
+  FrameTreeNode* parent = FindFrameTreeNodeByID(parent_frame_id);
+  if (!parent)
+    return;
+
+  FrameTreeNode* node = new FrameTreeNode(frame_id, frame_name);
+  parent->AddChild(node);
+}
+
+void WebContentsImpl::OnFrameDetached(int64 parent_frame_id, int64 frame_id) {
   FOR_EACH_OBSERVER(WebContentsObserver, observers_,
                     FrameDetached(message_source_, frame_id));
+
+  FrameTreeNode* parent = FindFrameTreeNodeByID(parent_frame_id);
+  if (!parent)
+    return;
+
+  parent->RemoveChild(frame_id);
 }
 
 void WebContentsImpl::DidChangeVisibleSSLState() {
@@ -2720,6 +2757,14 @@ void WebContentsImpl::RenderViewDeleted(RenderViewHost* rvh) {
 void WebContentsImpl::DidNavigate(
     RenderViewHost* rvh,
     const ViewHostMsg_FrameNavigate_Params& params) {
+  // If we don't have a frame tree root yet, this is the first navigation in
+  // using the current RenderViewHost, so we need to create it with the proper
+  // frame id.
+  if (!frame_tree_root_.get()) {
+    DCHECK(PageTransitionIsMainFrame(params.transition));
+    frame_tree_root_.reset(new FrameTreeNode(params.frame_id, std::string()));
+  }
+
   if (PageTransitionIsMainFrame(params.transition)) {
     // When overscroll navigation gesture is enabled, a screenshot of the page
     // in its current state is taken so that it can be used during the
@@ -2733,6 +2778,10 @@ void WebContentsImpl::DidNavigate(
     render_manager_.DidNavigateMainFrame(rvh);
   }
 
+  // We expect to have a valid frame tree root node at all times when
+  // navigating.
+  DCHECK(frame_tree_root_.get());
+
   // Update the site of the SiteInstance if it doesn't have one yet, unless
   // this is for about:blank.  In that case, the SiteInstance can still be
   // considered unused until a navigation to a real page.
@@ -3306,6 +3355,24 @@ void WebContentsImpl::NotifySwappedFromRenderManager(RenderViewHost* rvh) {
     view_->SetOverscrollControllerEnabled(delegate_->CanOverscrollContent());
 
   view_->RenderViewSwappedIn(render_manager_.current_host());
+
+  FrameTreeNode* root = NULL;
+  RenderViewHostImpl* new_rvh = static_cast<RenderViewHostImpl*>(
+      render_manager_.current_host());
+
+  // We are doing a cross-site navigation and swapping processes. Since frame
+  // ids are unique to a process, we need to recreate the frame tree with the
+  // proper main frame id.
+  // Note that it is possible for this method to be called before the new RVH
+  // has committed a navigation (if RenderViewHostManager short-circuits the
+  // CommitPending call because the current RVH is dead). In that case, we
+  // haven't heard a valid frame id to use to initialize the root node, so clear
+  // out the root node and the first subsequent navigation message will set it
+  // correctly.
+  if (new_rvh->main_frame_id() != -1)
+    root = new FrameTreeNode(new_rvh->main_frame_id(), std::string());
+
+  frame_tree_root_.reset(root);
 }
 
 int WebContentsImpl::CreateOpenerRenderViewsForRenderManager(
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 39cf2ae..a7a408b 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -14,6 +14,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/process.h"
+#include "content/browser/renderer_host/frame_tree_node.h"
 #include "content/browser/renderer_host/render_view_host_delegate.h"
 #include "content/browser/renderer_host/render_widget_host_delegate.h"
 #include "content/browser/web_contents/navigation_controller_impl.h"
@@ -184,6 +185,10 @@ class CONTENT_EXPORT WebContentsImpl
   void DragSourceMovedTo(int client_x, int client_y,
                          int screen_x, int screen_y);
 
+  FrameTreeNode* GetFrameTreeRootForTesting() {
+    return frame_tree_root_.get();
+  }
+
   // WebContents ------------------------------------------------------
   virtual WebContentsDelegate* GetDelegate() OVERRIDE;
   virtual void SetDelegate(WebContentsDelegate* delegate) OVERRIDE;
@@ -488,6 +493,7 @@ class CONTENT_EXPORT WebContentsImpl
   FRIEND_TEST_ALL_PREFIXES(WebContentsImplTest,
                            CrossSiteCantPreemptAfterUnload);
   FRIEND_TEST_ALL_PREFIXES(WebContentsImplTest, PendingContents);
+  FRIEND_TEST_ALL_PREFIXES(WebContentsImplTest, FrameTreeShape);
   FRIEND_TEST_ALL_PREFIXES(FormStructureBrowserTest, HTMLFiles);
   FRIEND_TEST_ALL_PREFIXES(NavigationControllerTest, HistoryNavigate);
   FRIEND_TEST_ALL_PREFIXES(RenderViewHostManagerTest, PageDoesBackAndReload);
@@ -588,7 +594,10 @@ class CONTENT_EXPORT WebContentsImpl
                           const std::vector<SkBitmap>& bitmaps);
   void OnUpdateFaviconURL(int32 page_id,
                           const std::vector<FaviconURL>& candidates);
-  void OnFrameDetached(int64 frame_id);
+  void OnFrameAttached(int64 parent_frame_id,
+                       int64 frame_id,
+                       const std::string& frame_name);
+  void OnFrameDetached(int64 parent_frame_id, int64 frame_id);
 
   // Changes the IsLoading state and notifies delegate as needed
   // |details| is used to provide details on the load that just finished
@@ -697,6 +706,8 @@ class CONTENT_EXPORT WebContentsImpl
 
   RenderViewHostImpl* GetRenderViewHostImpl();
 
+  FrameTreeNode* FindFrameTreeNodeByID(int64 frame_id);
+
   // Removes browser plugin embedder if there is one.
   void RemoveBrowserPluginEmbedder();
 
@@ -800,6 +811,9 @@ class CONTENT_EXPORT WebContentsImpl
   // True if this is a secure page which displayed insecure content.
   bool displayed_insecure_content_;
 
+  // The frame tree structure of the current page.
+  scoped_ptr<FrameTreeNode> frame_tree_root_;
+
   // Data for misc internal state ----------------------------------------------
 
   // When > 0, the WebContents is currently being captured (e.g., for
diff --git a/content/browser/web_contents/web_contents_impl_browsertest.cc b/content/browser/web_contents/web_contents_impl_browsertest.cc
index cfc5e08..66e0857 100644
--- a/content/browser/web_contents/web_contents_impl_browsertest.cc
+++ b/content/browser/web_contents/web_contents_impl_browsertest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/values.h"
+#include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/load_notification_details.h"
 #include "content/public/browser/navigation_controller.h"
@@ -121,4 +122,42 @@ IN_PROC_BROWSER_TEST_F(WebContentsImplBrowserTest,
             load_observer.controller_);
 }
 
+// Test that the browser receives the proper frame attach/detach messages from
+// the renderer and builds proper frame tree.
+IN_PROC_BROWSER_TEST_F(WebContentsImplBrowserTest, FrameTree) {
+  ASSERT_TRUE(test_server()->Start());
+
+  NavigateToURL(shell(), test_server()->GetURL("files/frame_tree/top.html"));
+
+  WebContentsImpl* wc = static_cast<WebContentsImpl*>(shell()->web_contents());
+  RenderViewHostImpl* rvh = static_cast<RenderViewHostImpl*>(
+      wc->GetRenderViewHost());
+  FrameTreeNode* root = wc->GetFrameTreeRootForTesting();
+
+  // Check that the root node is properly created with the frame id of the
+  // initial navigation.
+  EXPECT_EQ(3UL, root->child_count());
+  EXPECT_EQ(std::string(), root->frame_name());
+  EXPECT_EQ(rvh->main_frame_id(), root->frame_id());
+
+  EXPECT_EQ(2UL, root->child_at(0)->child_count());
+  EXPECT_STREQ("1-1-name", root->child_at(0)->frame_name().c_str());
+
+  // Verify the deepest node exists and has the right name.
+  EXPECT_EQ(2UL, root->child_at(2)->child_count());
+  EXPECT_EQ(1UL, root->child_at(2)->child_at(1)->child_count());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(1)->child_at(0)->child_count());
+  EXPECT_STREQ("3-1-id",
+      root->child_at(2)->child_at(1)->child_at(0)->frame_name().c_str());
+
+  // Navigate to about:blank, which should leave only the root node of the frame
+  // tree in the browser process.
+  NavigateToURL(shell(), test_server()->GetURL("files/title1.html"));
+
+  root = wc->GetFrameTreeRootForTesting();
+  EXPECT_EQ(0UL, root->child_count());
+  EXPECT_EQ(std::string(), root->frame_name());
+  EXPECT_EQ(rvh->main_frame_id(), root->frame_id());
+}
+
 }  // namespace content
diff --git a/content/browser/web_contents/web_contents_impl_unittest.cc b/content/browser/web_contents/web_contents_impl_unittest.cc
index cb702a4..6d79088 100644
--- a/content/browser/web_contents/web_contents_impl_unittest.cc
+++ b/content/browser/web_contents/web_contents_impl_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
+#include "content/browser/renderer_host/frame_tree_node.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/test_render_view_host.h"
 #include "content/browser/site_instance_impl.h"
@@ -2050,4 +2051,82 @@ TEST_F(WebContentsImplTest, PendingContents) {
   EXPECT_EQ(NULL, contents()->GetCreatedWindow(route_id));
 }
 
+// This test asserts the shape of the frame tree is correct, based on incoming
+// frame attached/detached messages.
+TEST_F(WebContentsImplTest, FrameTreeShape) {
+  std::string no_children_node("no children node");
+  std::string deep_subtree("node with deep subtree");
+
+  // The initial navigation will create a frame_tree_root_ node with the top
+  // level frame id. Simulate that by just creating it here.
+  contents()->frame_tree_root_.reset(
+      new FrameTreeNode(5, std::string("top-level")));
+
+  // Let's send a series of messages for frame attached and build the
+  // frame tree.
+  contents()->OnFrameAttached(5, 14, std::string());
+  contents()->OnFrameAttached(5, 15, std::string());
+  contents()->OnFrameAttached(5, 16, std::string());
+
+  contents()->OnFrameAttached(14, 244, std::string());
+  contents()->OnFrameAttached(14, 245, std::string());
+
+  contents()->OnFrameAttached(15, 255, no_children_node);
+
+  contents()->OnFrameAttached(16, 264, std::string());
+  contents()->OnFrameAttached(16, 265, std::string());
+  contents()->OnFrameAttached(16, 266, std::string());
+  contents()->OnFrameAttached(16, 267, deep_subtree);
+  contents()->OnFrameAttached(16, 268, std::string());
+
+  contents()->OnFrameAttached(267, 365, std::string());
+  contents()->OnFrameAttached(365, 455, std::string());
+  contents()->OnFrameAttached(455, 555, std::string());
+  contents()->OnFrameAttached(555, 655, std::string());
+
+  // Now, verify the tree structure is as expected.
+  FrameTreeNode* root = contents()->frame_tree_root_.get();
+  EXPECT_EQ(5, root->frame_id());
+  EXPECT_EQ(3UL, root->child_count());
+
+  EXPECT_EQ(2UL, root->child_at(0)->child_count());
+  EXPECT_EQ(0UL, root->child_at(0)->child_at(0)->child_count());
+  EXPECT_EQ(0UL, root->child_at(0)->child_at(1)->child_count());
+
+  EXPECT_EQ(1UL, root->child_at(1)->child_count());
+  EXPECT_EQ(0UL, root->child_at(1)->child_at(0)->child_count());
+  EXPECT_STREQ(no_children_node.c_str(),
+      root->child_at(1)->child_at(0)->frame_name().c_str());
+
+  EXPECT_EQ(5UL, root->child_at(2)->child_count());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(0)->child_count());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(1)->child_count());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(2)->child_count());
+  EXPECT_EQ(1UL, root->child_at(2)->child_at(3)->child_count());
+  EXPECT_STREQ(deep_subtree.c_str(),
+      root->child_at(2)->child_at(3)->frame_name().c_str());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(4)->child_count());
+
+  FrameTreeNode* deep_tree = root->child_at(2)->child_at(3)->child_at(0);
+  EXPECT_EQ(365, deep_tree->frame_id());
+  EXPECT_EQ(1UL, deep_tree->child_count());
+  EXPECT_EQ(455, deep_tree->child_at(0)->frame_id());
+  EXPECT_EQ(1UL, deep_tree->child_at(0)->child_count());
+  EXPECT_EQ(555, deep_tree->child_at(0)->child_at(0)->frame_id());
+  EXPECT_EQ(1UL, deep_tree->child_at(0)->child_at(0)->child_count());
+  EXPECT_EQ(655, deep_tree->child_at(0)->child_at(0)->child_at(0)->frame_id());
+  EXPECT_EQ(0UL,
+      deep_tree->child_at(0)->child_at(0)->child_at(0)->child_count());
+
+  // Test removing of nodes.
+  contents()->OnFrameDetached(555, 655);
+  EXPECT_EQ(0UL, deep_tree->child_at(0)->child_at(0)->child_count());
+
+  contents()->OnFrameDetached(16, 265);
+  EXPECT_EQ(4UL, root->child_at(2)->child_count());
+
+  contents()->OnFrameDetached(5, 15);
+  EXPECT_EQ(2UL, root->child_count());
+}
+
 }  // namespace content
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index 2f3756e..0a5cc0b 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -2172,8 +2172,17 @@ IPC_MESSAGE_CONTROL3(ViewHostMsg_DidLose3DContext,
                      content::ThreeDAPIType /* context_type */,
                      int /* arb_robustness_status_code */)
 
-// Notifies the browser that the frame with the given id was detached.
-IPC_MESSAGE_ROUTED1(ViewHostMsg_FrameDetached,
+// This message is sent when a frame is added to the DOM.
+IPC_MESSAGE_ROUTED3(ViewHostMsg_FrameAttached,
+                    int64 /* parent_frame_id*/,
+                    int64 /* frame_id */,
+                    std::string /* frame_name */)
+
+// Notifies the browser that the frame with the given id was detached. The
+// |parent_frame_id| is -1 for the top level frame, otherwise the id of the
+// immediate parent of the detached frame.
+IPC_MESSAGE_ROUTED2(ViewHostMsg_FrameDetached,
+                    int64 /* parent_frame_id */,
                     int64 /* frame_id */)
 
 // Notifies the browser that document has parsed the body. This is used by the
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 37b5aee..fc2071b 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -682,6 +682,8 @@
     'browser/renderer_host/dip_util.h',
     'browser/renderer_host/file_utilities_message_filter.cc',
     'browser/renderer_host/file_utilities_message_filter.h',
+    'browser/renderer_host/frame_tree_node.cc',
+    'browser/renderer_host/frame_tree_node.h',
     'browser/renderer_host/gamepad_browser_message_filter.cc',
     'browser/renderer_host/gamepad_browser_message_filter.h',
     'browser/renderer_host/gesture_event_filter.cc',
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 56ff217..a24e962 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -2776,6 +2776,8 @@ WebCookieJar* RenderViewImpl::cookieJar(WebFrame* frame) {
 }
 
 void RenderViewImpl::didCreateFrame(WebFrame* parent, WebFrame* child) {
+  Send(new ViewHostMsg_FrameAttached(routing_id_, parent->identifier(),
+      child->identifier(), UTF16ToUTF8(child->assignedName())));
 }
 
 void RenderViewImpl::didDisownOpener(WebKit::WebFrame* frame) {
@@ -2791,7 +2793,12 @@ void RenderViewImpl::didDisownOpener(WebKit::WebFrame* frame) {
 }
 
 void RenderViewImpl::frameDetached(WebFrame* frame) {
-  Send(new ViewHostMsg_FrameDetached(routing_id_, frame->identifier()));
+  int64 parent_frame_id = -1;
+  if (frame->parent())
+    parent_frame_id = frame->parent()->identifier();
+
+  Send(new ViewHostMsg_FrameDetached(routing_id_, parent_frame_id,
+      frame->identifier()));
 
   FOR_EACH_OBSERVER(RenderViewObserver, observers_, FrameDetached(frame));
 }
diff --git a/content/test/data/frame_tree/2-4.html b/content/test/data/frame_tree/2-4.html
index 3bdea4b..3767f39 100644
--- a/content/test/data/frame_tree/2-4.html
+++ b/content/test/data/frame_tree/2-4.html
@@ -6,7 +6,7 @@
 Frame 2-4.
 <br>
 
-<iframe src="3-1.html"></iframe>
+<iframe id='3-1-id' src="3-1.html"></iframe>
 
 </body>
 </html>