Fix Volume slider is captured in screenshot done in touchview mode

ash/common/system/tray/system_tray_notifier.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/system/tray/system_tray_notifier.h"
 
 #include "ash/common/system/accessibility_observer.h"
 #include "ash/common/system/audio/audio_observer.h"
 #include "ash/common/system/date/clock_observer.h"
 #include "ash/common/system/ime/ime_observer.h"
 #include "ash/common/system/update/update_observer.h"
 #include "ash/common/system/user/user_observer.h"
+#include "ash/common/wm/maximize_mode/maximize_mode_screenshot_observer.h"
 
 #if defined(OS_CHROMEOS)
 #include "ash/common/system/chromeos/bluetooth/bluetooth_observer.h"
 #include "ash/common/system/chromeos/enterprise/enterprise_domain_observer.h"
 #include "ash/common/system/chromeos/media_security/media_capture_observer.h"
 #include "ash/common/system/chromeos/network/network_observer.h"
 #include "ash/common/system/chromeos/network/network_portal_detector_observer.h"
 #include "ash/common/system/chromeos/screen_security/screen_capture_observer.h"
 #include "ash/common/system/chromeos/screen_security/screen_share_observer.h"
 #include "ash/common/system/chromeos/session/last_window_closed_observer.h"
@@ skipping 112 matching lines @@
 
 void SystemTrayNotifier::NotifyLocaleChanged(LocaleObserver::Delegate* delegate,
                                              const std::string& cur_locale,
                                              const std::string& from_locale,
                                              const std::string& to_locale) {
   FOR_EACH_OBSERVER(
       LocaleObserver, locale_observers_,
       OnLocaleChanged(delegate, cur_locale, from_locale, to_locale));
 }
 
+void SystemTrayNotifier::AddMaxModeScreenshotObserver(
+    MaximizeModeScreenshotObserver* observer) {
+  maximize_mode_screenshot_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::RemoveMaxModeScreenshotObserver(
+    MaximizeModeScreenshotObserver* observer) {
+  maximize_mode_screenshot_observers_.RemoveObserver(observer);
+}
+
+void SystemTrayNotifier::NotifyWillTakeScreenshot(int volume_percent) {
+  FOR_EACH_OBSERVER(MaximizeModeScreenshotObserver,
+                    maximize_mode_screenshot_observers_,
+                    OnWillTakeScreenshot(volume_percent));
+}
+
+void SystemTrayNotifier::NotifyDidTakeScreenshot() {
+  FOR_EACH_OBSERVER(MaximizeModeScreenshotObserver,
+                    maximize_mode_screenshot_observers_, OnDidTakeScreenshot());
+}
+
 void SystemTrayNotifier::AddUpdateObserver(UpdateObserver* observer) {
   update_observers_.AddObserver(observer);
 }
 
 void SystemTrayNotifier::RemoveUpdateObserver(UpdateObserver* observer) {
   update_observers_.RemoveObserver(observer);
 }
 
 void SystemTrayNotifier::NotifyUpdateRecommended(const UpdateInfo& info) {
   FOR_EACH_OBSERVER(UpdateObserver, update_observers_,
@@ skipping 219 matching lines @@
 
 void SystemTrayNotifier::NotifyVirtualKeyboardSuppressionChanged(
     bool suppressed) {
   FOR_EACH_OBSERVER(VirtualKeyboardObserver, virtual_keyboard_observers_,
                     OnKeyboardSuppressionChanged(suppressed));
 }
 
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace ash