Allow the user to cancel the capture region action, and show its active status in the tray.

ash/common/test/test_palette_delegate.cc

 // Copyright 2016 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/common/test/test_palette_delegate.h"
 
 namespace ash {
 
 TestPaletteDelegate::TestPaletteDelegate() {}
 
@@ skipping 27 matching lines @@
 }
 
 bool TestPaletteDelegate::ShouldShowPalette() {
   return should_show_palette_;
 }
 
 void TestPaletteDelegate::TakeScreenshot() {
   ++take_screenshot_count_;
 }
 
-void TestPaletteDelegate::TakePartialScreenshot() {
+void TestPaletteDelegate::TakePartialScreenshot(const base::Closure& done) {
   ++take_partial_screenshot_count_;
+  partial_screenshot_done_ = done;
 }
 
+void TestPaletteDelegate::CancelPartialScreenshot() {}
+
 }  // namespace ash