Makes drops above the tabstrip work again. This stopped working...

chrome/browser/views/frame/browser_root_view.h

+// Copyright (c) 2009 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 CHROME_BROWSER_VIEWS_FRAME_BROWSER_ROOT_VIEW_H
+#define CHROME_BROWSER_VIEWS_FRAME_BROWSER_ROOT_VIEW_H
+
+#include "chrome/views/root_view.h"
+
+class OSExchangeData;
+class TabStrip;
+
+// RootView implementation used by BrowserFrame. This forwards drop events to
+// the TabStrip. Visually the tabstrip extends to the top of the frame, but in
+// actually it doesn't. The tabstrip is only as high as a tab. To enable
+// dropping above the tabstrip BrowserRootView forwards drop events to the
+// TabStrip.
+class BrowserRootView : public views::RootView {
+ public:
+  explicit BrowserRootView(views::Widget* widget);
+
+  virtual bool CanDrop(const OSExchangeData& data);
+  virtual void OnDragEntered(const views::DropTargetEvent& event);
+  virtual int OnDragUpdated(const views::DropTargetEvent& event);
+  virtual void OnDragExited();
+  virtual int OnPerformDrop(const views::DropTargetEvent& event);
+
+ private:
+  // Returns true if the event should be forwarded to the tabstrip.
+  bool ShouldForwardToTabStrip(const views::DropTargetEvent& event);
+
+  // Converts the event from the hosts coordinate system to the tabstrips
+  // coordinate system.
+  views::DropTargetEvent* MapEventToTabStrip(
+      const views::DropTargetEvent& event);
+
+  // The TabStrip.
+  TabStrip* tabstrip_;
+
+  // Is a drop allowed? This is set by CanDrop.
+  bool can_drop_;
+
+  // If true, drag and drop events are being forwarded to the tab strip.
+  // This is used to determine when to send OnDragEntered and OnDragExited
+  // to the tab strip.
+  bool forwarding_to_tab_strip_;
+
+  DISALLOW_COPY_AND_ASSIGN(BrowserRootView);
+};
+
+#endif  // CHROME_BROWSER_VIEWS_FRAME_BROWSER_ROOT_VIEW_H