Return false in AcceleratorController::Process() if an accelerator has no effect

ash/accelerators/accelerator_controller.cc

 // 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.
 
 #include "ash/accelerators/accelerator_controller.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 
@@ skipping 162 matching lines @@
     float scale =
         ash::Shell::GetInstance()->magnification_controller()->GetScale();
     // Calculate rounded logarithm (base kMagnificationScaleFactor) of scale.
     int scale_index =
         std::floor(std::log(scale) / std::log(kMagnificationScaleFactor) + 0.5);
 
     int new_scale_index = std::max(0, std::min(8, scale_index + delta_index));
 
     ash::Shell::GetInstance()->magnification_controller()->
         SetScale(std::pow(kMagnificationScaleFactor, new_scale_index), true);
+    return true;
   } else if (ash::Shell::GetInstance()->
              partial_magnification_controller()->is_enabled()) {
     float scale = delta_index > 0 ? kDefaultPartialMagnifiedScale : 1;
     ash::Shell::GetInstance()->partial_magnification_controller()->
         SetScale(scale);
+    return true;
   }
-
-  return true;
+  return false;
 }
 
 bool HandleMediaNextTrack() {
   Shell::GetInstance()->media_delegate()->HandleMediaNextTrack();
   return true;
 }
 
 bool HandleMediaPlayPause() {
   Shell::GetInstance()->media_delegate()->HandleMediaPlayPause();
   return true;
@@ skipping 148 matching lines @@
 }
 
 bool HandleScaleReset() {
   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
   int64 display_id = display_manager->GetDisplayIdForUIScaling();
   if (display_id == gfx::Display::kInvalidDisplayID)
     return false;
 
   base::RecordAction(UserMetricsAction("Accel_Scale_Ui_Reset"));
 
-  display_manager->SetDisplayUIScale(display_id, 1.0f);
-  return true;
+  float ui_scale =
+      display_manager->GetDisplayInfo(display_id).configured_ui_scale();
+  if (ui_scale != 1.0f) {
+    display_manager->SetDisplayUIScale(display_id, 1.0f);
+    return true;
+  }
+  return false;
 }
 
 bool HandleScaleUI(bool up) {
   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
   int64 display_id = display_manager->GetDisplayIdForUIScaling();
   if (display_id == gfx::Display::kInvalidDisplayID)
     return false;
 
   if (up) {
     base::RecordAction(UserMetricsAction("Accel_Scale_Ui_Up"));
@@ skipping 15 matching lines @@
 }
 #endif
 
 bool HandleShowKeyboardOverlay() {
   base::RecordAction(UserMetricsAction("Accel_Show_Keyboard_Overlay"));
   ash::Shell::GetInstance()->new_window_delegate()->ShowKeyboardOverlay();
 
   return true;
 }
 
-void HandleShowMessageCenterBubble() {
+bool HandleShowMessageCenterBubble() {
   base::RecordAction(UserMetricsAction("Accel_Show_Message_Center_Bubble"));
   RootWindowController* controller =
       RootWindowController::ForTargetRootWindow();
   StatusAreaWidget* status_area_widget =
       controller->shelf()->status_area_widget();
   if (status_area_widget) {
     WebNotificationTray* notification_tray =
       status_area_widget->web_notification_tray();
-    if (notification_tray->visible())
+    if (notification_tray->visible()) {
       notification_tray->ShowMessageCenterBubble();
+      return true;
+    }
   }
+  return false;
 }
 
 bool HandleShowSystemTrayBubble() {
   base::RecordAction(UserMetricsAction("Accel_Show_System_Tray_Bubble"));
   RootWindowController* controller =
       RootWindowController::ForTargetRootWindow();
   if (!controller->GetSystemTray()->HasSystemBubble()) {
     controller->GetSystemTray()->ShowDefaultView(BUBBLE_CREATE_NEW);
     return true;
   }
@@ skipping 587 matching lines @@
       return HandleFocusShelf();
     case FOCUS_NEXT_PANE:
       return HandleRotatePaneFocus(Shell::FORWARD);
     case FOCUS_PREVIOUS_PANE:
       return HandleRotatePaneFocus(Shell::BACKWARD);
     case SHOW_KEYBOARD_OVERLAY:
       return HandleShowKeyboardOverlay();
     case SHOW_SYSTEM_TRAY_BUBBLE:
       return HandleShowSystemTrayBubble();
     case SHOW_MESSAGE_CENTER_BUBBLE:
-      HandleShowMessageCenterBubble();
-      break;
+      return HandleShowMessageCenterBubble();
     case SHOW_TASK_MANAGER:
       return HandleShowTaskManager();
     case NEXT_IME:
       HandleNextIme(
           ime_control_delegate_.get(), previous_event_type, previous_key_code);
       // NEXT_IME is bound to Alt-Shift key up event. To be consistent with
       // Windows behavior, do not consume the key event here.
       return false;
     case PREVIOUS_IME:
       return HandlePreviousIme(ime_control_delegate_.get(), accelerator);
@@ skipping 185 matching lines @@
     keyboard_brightness_control_delegate) {
   keyboard_brightness_control_delegate_ =
       keyboard_brightness_control_delegate.Pass();
 }
 
 bool AcceleratorController::CanHandleAccelerators() const {
   return true;
 }
 
 }  // namespace ash