Support frame tree propagation between renderers in the same browsing instance.

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index 95e3e9280fcc35a1a836f0a5c5f5ac581bce4693..619e31ca551bbdcd3f47330404b7a433a542f837 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -12,6 +12,7 @@
 #include "base/command_line.h"
 #include "base/i18n/rtl.h"
 #include "base/json/json_reader.h"
+#include "base/json/json_writer.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
 #include "base/string_util.h"
@@ -943,6 +944,7 @@ bool RenderViewHostImpl::OnMessageReceived(const IPC::Message& msg) {
                         OnDomOperationResponse)
     IPC_MESSAGE_HANDLER(AccessibilityHostMsg_Notifications,
                         OnAccessibilityNotifications)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_FrameTree, OnFrameTree)
     // Have the super handle all other messages.
     IPC_MESSAGE_UNHANDLED(
         handled = RenderWidgetHostImpl::OnMessageReceived(msg))
@@ -1147,6 +1149,21 @@ void RenderViewHostImpl::OnMsgNavigate(const IPC::Message& msg) {
   FilterURL(policy, renderer_id, true, &validated_params.password_form.action);
 
   delegate_->DidNavigate(this, validated_params);
+
+  // For top level navigations, if there is no frame tree present for this
+  // instance (for example when the window is first created), then create
+  // an unnamed one with the proper frame id from the renderer.
+  // This should be done after we called DidNavigate, since updating the frame
+  // tree expects the render view being updated to be the active one.
+  if (content::PageTransitionIsMainFrame(validated_params.transition)) {
+    if (frame_tree_.empty()) {
+      base::DictionaryValue tree;
+      tree.SetString("name", std::string());
+      tree.SetInteger("id", validated_params.frame_id);
+      base::JSONWriter::Write(&tree, &frame_tree_);
+      delegate_->DidUpdateFrameTree(this);
+    }
+  }
 }
 
 void RenderViewHostImpl::OnMsgUpdateState(int32 page_id,
@@ -1633,6 +1650,20 @@ webkit_glue::WebPreferences RenderViewHostImpl::GetWebkitPreferences() {
   return delegate_->GetWebkitPrefs();
 }
 
+const std::string& RenderViewHostImpl::GetFrameTree() const {
+  return frame_tree_;
+}
+
+void RenderViewHostImpl::UpdateFrameTree(
+    int process_id, int route_id, const std::string& frame_tree) {
+  frame_tree_ = frame_tree;
+
+  Send(new ViewMsg_FrameTree(GetRoutingID(),
+                             process_id,
+                             route_id,
+                             frame_tree_));
+}
+
 void RenderViewHostImpl::UpdateWebkitPreferences(
     const webkit_glue::WebPreferences& prefs) {
   Send(new ViewMsg_UpdateWebPreferences(GetRoutingID(), prefs));
@@ -1868,6 +1899,11 @@ void RenderViewHostImpl::OnDomOperationResponse(
       content::Details<DomOperationNotificationDetails>(&details));
 }
 
+void RenderViewHostImpl::OnFrameTree(const std::string& frame_tree) {
+  frame_tree_ = frame_tree;
+  delegate_->DidUpdateFrameTree(this);
+}
+
 void RenderViewHostImpl::SetSwappedOut(bool is_swapped_out) {
   is_swapped_out_ = is_swapped_out;