Update selection region style

ash/utility/screenshot_controller_unittest.cc

 // Copyright 2014 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 "ash/utility/screenshot_controller.h"
 
 #include "ash/display/cursor_window_controller.h"
 #include "ash/display/mouse_cursor_event_filter.h"
 #include "ash/display/window_tree_host_manager.h"
 #include "ash/screenshot_delegate.h"
@@ skipping 203 matching lines @@
 
   GetEventGenerator().PressKey(ui::VKEY_A, 0);
   GetEventGenerator().ReleaseKey(ui::VKEY_A, 0);
 
   EXPECT_FALSE(client->IsCursorVisible());
 
   StartPartialScreenshotSession();
   EXPECT_TRUE(IsActive());
   EXPECT_TRUE(client->IsCursorVisible());
 
+  // Platform's Cursor should be hidden while dragging.
+  GetEventGenerator().PressLeftButton();
+  EXPECT_TRUE(IsActive());
+  EXPECT_FALSE(client->IsCursorVisible());
+
   Cancel();
   EXPECT_TRUE(client->IsCursorVisible());
 }
 
 // Make sure ScreenshotController doesn't prevent handling of large
 // cursor. See http://crbug.com/459214
 TEST_F(PartialScreenshotControllerTest, LargeCursor) {
   Shell::GetInstance()->cursor_manager()->SetCursorSet(ui::CURSOR_SET_LARGE);
   Shell::GetInstance()
       ->window_tree_host_manager()
@@ skipping 171 matching lines @@
   EXPECT_FALSE(IsActive());
 
   StartWindowScreenshotSession();
   EXPECT_TRUE(IsActive());
   UpdateDisplay("400x400");
   RunAllPendingInMessageLoop();
   EXPECT_FALSE(IsActive());
 }
 
 }  // namespace ash