Browser Plugin: Add HTML5-like postMessage support

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 308f0d6959afbde603dfff151fb8dc02d4b170b5..4120e19007d764c2499334530b2508725849baaf 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -374,6 +374,9 @@ static RenderViewImpl* FromRoutingID(int32 routing_id) {
 }
 
 static WebKit::WebFrame* FindFrameByID(WebKit::WebFrame* root, int frame_id) {
+  if (frame_id == -1)
+    return root;
+
   for (WebFrame* frame = root; frame; frame = frame->traverseNext(false)) {
     if (frame->identifier() == frame_id)
       return frame;
@@ -3820,6 +3823,9 @@ void RenderViewImpl::CreateFrameTree(WebKit::WebFrame* frame,
 }
 
 WebKit::WebFrame* RenderViewImpl::GetFrameByMappedID(int frame_id) {
+  if (frame_id == -1)
+    return webview()->mainFrame();
+
   std::map<int, int>::iterator it = active_frame_id_map_.find(frame_id);
   if (it == active_frame_id_map_.end())
     return NULL;
@@ -6152,10 +6158,15 @@ void RenderViewImpl::OnUpdatedFrameTree(
     int process_id,
     int route_id,
     const std::string& frame_tree) {
+  if (frame_tree.empty())
+    return;
+
   base::DictionaryValue* frames = NULL;
   scoped_ptr<base::Value> tree(base::JSONReader::Read(frame_tree));
-  if (tree.get() && tree->IsType(base::Value::TYPE_DICTIONARY))
-    tree->GetAsDictionary(&frames);
+  if (tree.get() && tree->IsType(base::Value::TYPE_DICTIONARY)) {
+    if (!tree->GetAsDictionary(&frames))
+      return;
+  }
 
   updating_frame_tree_ = true;
   active_frame_id_map_.clear();