Fixed drag and drop into and out of Browser Plugin.

content/browser/web_contents/web_drag_source_win.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_drag_source_win.h"
 
 #include "base/bind.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
+#include "content/browser/web_contents/web_contents_impl.h"
 #include "content/browser/web_contents/web_drag_utils_win.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/notification_types.h"
-#include "content/public/browser/web_contents.h"
 
 using WebKit::WebDragOperationNone;
 
 namespace content {
 namespace {
 
 static void GetCursorPositions(gfx::NativeWindow wnd, gfx::Point* client,
                                gfx::Point* screen) {
   POINT cursor_pos;
   GetCursorPos(&cursor_pos);
   screen->SetPoint(cursor_pos.x, cursor_pos.y);
   ScreenToClient(wnd, &cursor_pos);
   client->SetPoint(cursor_pos.x, cursor_pos.y);
 }
 
 }  // namespace
 
 ///////////////////////////////////////////////////////////////////////////////
 // WebDragSource, public:
 
 WebDragSource::WebDragSource(gfx::NativeWindow source_wnd,
                              WebContents* web_contents)
     : ui::DragSourceWin(),
       source_wnd_(source_wnd),
-      render_view_host_(web_contents->GetRenderViewHost()),
+      web_contents_(static_cast<WebContentsImpl*>(web_contents)),
       effect_(DROPEFFECT_NONE) {
   registrar_.Add(this, NOTIFICATION_WEB_CONTENTS_SWAPPED,
                  Source<WebContents>(web_contents));
   registrar_.Add(this, NOTIFICATION_WEB_CONTENTS_DISCONNECTED,
                  Source<WebContents>(web_contents));
 }
 
 WebDragSource::~WebDragSource() {
 }
 
 void WebDragSource::OnDragSourceCancel() {
   // Delegate to the UI thread if we do drag-and-drop in the background thread.
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE,
         base::Bind(&WebDragSource::OnDragSourceCancel, this));
     return;
   }
 
-  if (!render_view_host_)
+  if (!web_contents_)
     return;
 
   gfx::Point client;
   gfx::Point screen;
   GetCursorPositions(source_wnd_, &client, &screen);
-  render_view_host_->DragSourceEndedAt(client.x(), client.y(),
-                                       screen.x(), screen.y(),
-                                       WebDragOperationNone);
+  web_contents_->DragSourceEndedAt(client.x(), client.y(),
+                                   screen.x(), screen.y(),
+                                   WebDragOperationNone);
 }
 
 void WebDragSource::OnDragSourceDrop() {
   // On Windows, we check for drag end in IDropSource::QueryContinueDrag which
   // happens before IDropTarget::Drop is called. HTML5 requires the "dragend"
   // event to happen after the "drop" event. Since  Windows calls these two
   // directly after each other we can just post a task to handle the
   // OnDragSourceDrop after the current task.
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&WebDragSource::DelayedOnDragSourceDrop, this));
 }
 
 void WebDragSource::DelayedOnDragSourceDrop() {
-  if (!render_view_host_)
+  if (!web_contents_)
     return;
 
   gfx::Point client;
   gfx::Point screen;
   GetCursorPositions(source_wnd_, &client, &screen);
-  render_view_host_->DragSourceEndedAt(
-      client.x(), client.y(), screen.x(), screen.y(),
-      WinDragOpToWebDragOp(effect_));
+  web_contents_->DragSourceEndedAt(client.x(), client.y(), screen.x(),
+                                   screen.y(), WinDragOpToWebDragOp(effect_));
 }
 
 void WebDragSource::OnDragSourceMove() {
   // Delegate to the UI thread if we do drag-and-drop in the background thread.
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE,
         base::Bind(&WebDragSource::OnDragSourceMove, this));
     return;
   }
 
-  if (!render_view_host_)
+  if (!web_contents_)
     return;
 
   gfx::Point client;
   gfx::Point screen;
   GetCursorPositions(source_wnd_, &client, &screen);
-  render_view_host_->DragSourceMovedTo(client.x(), client.y(),
-                                       screen.x(), screen.y());
+  web_contents_->DragSourceMovedTo(client.x(), client.y(),
+                                   screen.x(), screen.y());
 }
 
 void WebDragSource::Observe(int type,
                             const NotificationSource& source,
                             const NotificationDetails& details) {
   if (type == NOTIFICATION_WEB_CONTENTS_SWAPPED) {
     // When the WebContents get swapped, our render view host goes away.
     // That's OK, we can continue the drag, we just can't send messages back to
     // our drag source.
-    render_view_host_ = NULL;
+    web_contents_ = NULL;
   } else if (type == NOTIFICATION_WEB_CONTENTS_DISCONNECTED) {
     // This could be possible when we close the tab and the source is still
     // being used in DoDragDrop at the time that the virtual file is being
     // downloaded.
-    render_view_host_ = NULL;
+    web_contents_ = NULL;
   }
 }
 
 }  // namespace content