aura: Fix a couple of bug (really the same bug at two different places) for drag

content/browser/web_contents/web_contents_view_aura.cc

 // Copyright (c) 2012 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/web_contents/web_contents_view_aura.h"
 
 #include "base/utf_string_conversions.h"
 #include "content/browser/renderer_host/render_view_host_factory.h"
 #include "content/browser/web_contents/interstitial_page_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
@@ skipping 161 matching lines @@
 // WebContentsViewAura, public:
 
 WebContentsViewAura::WebContentsViewAura(
     WebContentsImpl* web_contents,
     content::WebContentsViewDelegate* delegate)
     : web_contents_(web_contents),
       view_(NULL),
       delegate_(delegate),
       current_drag_op_(WebKit::WebDragOperationNone),
       close_tab_after_drag_ends_(false),
-      drag_dest_delegate_(NULL) {
+      drag_dest_delegate_(NULL),
+      current_rvh_for_drag_(NULL) {
 }
 
 WebContentsViewAura::~WebContentsViewAura() {
   // Window needs a valid delegate during its destructor, so we explicitly
   // delete it here.
   window_.reset();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // WebContentsViewAura, private:
@@ skipping 383 matching lines @@
 void WebContentsViewAura::OnDragEntered(const aura::DropTargetEvent& event) {
   if (drag_dest_delegate_)
     drag_dest_delegate_->DragInitialize(web_contents_);
 
   WebDropData drop_data;
   PrepareWebDropData(&drop_data, event.data());
   WebKit::WebDragOperationsMask op = ConvertToWeb(event.source_operations());
 
   gfx::Point screen_pt =
       GetNativeView()->GetRootWindow()->last_mouse_location();
+  current_rvh_for_drag_ = web_contents_->GetRenderViewHost();
   web_contents_->GetRenderViewHost()->DragTargetDragEnter(
       drop_data, event.location(), screen_pt, op);
 
   if (drag_dest_delegate_) {
     drag_dest_delegate_->OnReceiveDragData(event.data());
     drag_dest_delegate_->OnDragEnter();
   }
 }
 
 int WebContentsViewAura::OnDragUpdated(const aura::DropTargetEvent& event) {
+  DCHECK(current_rvh_for_drag_);
+  if (current_rvh_for_drag_ != web_contents_->GetRenderViewHost())
+    OnDragEntered(event);
+
   WebKit::WebDragOperationsMask op = ConvertToWeb(event.source_operations());
   gfx::Point screen_pt =
       GetNativeView()->GetRootWindow()->last_mouse_location();
   web_contents_->GetRenderViewHost()->DragTargetDragOver(
       event.location(), screen_pt, op);
 
   if (drag_dest_delegate_)
     drag_dest_delegate_->OnDragOver();
 
   return ConvertFromWeb(current_drag_op_);
 }
 
 void WebContentsViewAura::OnDragExited() {
+  DCHECK(current_rvh_for_drag_);
+  if (current_rvh_for_drag_ != web_contents_->GetRenderViewHost())
+    return;
+
   web_contents_->GetRenderViewHost()->DragTargetDragLeave();
   if (drag_dest_delegate_)
     drag_dest_delegate_->OnDragLeave();
 }
 
 int WebContentsViewAura::OnPerformDrop(const aura::DropTargetEvent& event) {
+  DCHECK(current_rvh_for_drag_);
+  if (current_rvh_for_drag_ != web_contents_->GetRenderViewHost())
+    OnDragEntered(event);
+
   web_contents_->GetRenderViewHost()->DragTargetDrop(
       event.location(),
       GetNativeView()->GetRootWindow()->last_mouse_location());
   if (drag_dest_delegate_)
     drag_dest_delegate_->OnDrop();
   return current_drag_op_;
 }