Add support for taking partial screenshot using touch

ash/wm/partial_screenshot_view.h

 // 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.
 
 #ifndef ASH_WM_PARTIAL_SCREENSHOT_VIEW_H_
 #define ASH_WM_PARTIAL_SCREENSHOT_VIEW_H_
 
+#include <vector>
+
 #include "ash/ash_export.h"
 #include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
 #include "ui/gfx/point.h"
 #include "ui/views/widget/widget_delegate.h"
 
 namespace aura {
 class RootWindow;
 }
 
 namespace ash {
 class ScreenshotDelegate;
 
 // The view of taking partial screenshot, i.e.: drawing region
 // rectangles during drag, and changing the mouse cursor to indicate
 // the current mode.
 class ASH_EXPORT PartialScreenshotView : public views::WidgetDelegateView {
  public:
   // Starts the UI for taking partial screenshot; dragging to select a region.
-  static void StartPartialScreenshot(ScreenshotDelegate* screenshot_delegate);
+  static std::vector<PartialScreenshotView*>
+      StartPartialScreenshot(ScreenshotDelegate* screenshot_delegate);
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(PartialScreenshotViewTest, BasicMouse);
+  FRIEND_TEST_ALL_PREFIXES(PartialScreenshotViewTest, BasicTouch);
+
   class OverlayDelegate;
 
   PartialScreenshotView(OverlayDelegate* overlay_delegate,
                         ScreenshotDelegate* screenshot_delegate);
   virtual ~PartialScreenshotView();
 
   // Initializes partial screenshot UI widget for |root_window|.
   void Init(aura::RootWindow* root_window);
 
   // Returns the currently selected region.
@@ skipping 22 matching lines @@
 
   // ScreenshotDelegate to take the actual screenshot. No ownership.
   ScreenshotDelegate* screenshot_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(PartialScreenshotView);
 };
 
 }  // namespace ash
 
 #endif  // #ifndef ASH_WM_PARTIAL_SCREENSHOT_VIEW_H_