Simplify AcceleratorDelegate interface

ash/accelerators/accelerator_delegate.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/accelerators/accelerator_delegate.h"
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/shell.h"
 #include "ash/wm/window_state.h"
 #include "ui/base/accelerators/accelerator.h"
 #include "ui/events/event.h"
 #include "ui/wm/core/window_util.h"
 
 namespace ash {
 namespace {}  // namespace
 
 AcceleratorDelegate::AcceleratorDelegate() {
 }
 AcceleratorDelegate::~AcceleratorDelegate() {
 }
 
 void AcceleratorDelegate::PreProcessAccelerator(
     const ui::Accelerator& accelerator) {
   // Fill out context object so AcceleratorController will know what
   // was the previous accelerator or if the current accelerator is repeated.
   Shell::GetInstance()->accelerator_controller()->context()->UpdateContext(
       accelerator);
 }
 
+bool AcceleratorDelegate::ProcessAccelerator(const ui::KeyEvent& key_event,
+                                             const ui::Accelerator& accelerator,
+                                             KeyType key_type) {
+  // Special hardware keys like brightness and volume are handled in
+  // special way. However, some windows can override this behavior
+  // (e.g. Chrome v1 apps by default and Chrome v2 apps with
+  // permission) by setting a window property.
+  if (key_type == SYSTEM_KEYS && !CanConsumeSystemKeys(key_event)) {
+    // System keys are always consumed regardless of whether they trigger an
+    // accelerator to prevent windows from seeing unexpected key up events.
+    Shell::GetInstance()->accelerator_controller()->Process(accelerator);
+    return true;
+  }
+  if (key_type == NORMAL_KEYS &&
+      !ShouldProcessAcceleratorNow(key_event, accelerator)) {
+    return false;
+  }
+  return Shell::GetInstance()->accelerator_controller()->Process(accelerator);
+}
+
 // Uses the top level window so if the target is a web contents window the
 // containing parent window will be checked for the property.
 bool AcceleratorDelegate::CanConsumeSystemKeys(const ui::KeyEvent& event) {
   aura::Window* target = static_cast<aura::Window*>(event.target());
-  if (!target)  // Can be NULL in tests.
-    return false;
+  DCHECK(target);
   aura::Window* top_level = ::wm::GetToplevelWindow(target);
   return top_level && wm::GetWindowState(top_level)->can_consume_system_keys();
 }
 
 // Returns true if the |accelerator| should be processed now, inside Ash's env
 // event filter.
 bool AcceleratorDelegate::ShouldProcessAcceleratorNow(
     const ui::KeyEvent& event,
     const ui::Accelerator& accelerator) {
   aura::Window* target = static_cast<aura::Window*>(event.target());
-  if (!target)
-    return true;
-
+  DCHECK(target);
   aura::Window::Windows root_windows = Shell::GetAllRootWindows();
   if (std::find(root_windows.begin(), root_windows.end(), target) !=
       root_windows.end())
     return true;
 
   // A full screen window should be able to handle all key events including the
   // reserved ones.
-  if (wm::GetWindowState(target)->IsFullscreen()) {
+  aura::Window* top_level = ::wm::GetToplevelWindow(target);
+
+  if (top_level && wm::GetWindowState(top_level)->IsFullscreen()) {
     // TODO(yusukes): On Chrome OS, only browser and flash windows can be full
     // screen. Launching an app in "open full-screen" mode is not supported yet.
     // That makes the IsWindowFullscreen() check above almost meaningless
     // because a browser and flash window do handle Ash accelerators anyway
     // before they're passed to a page or flash content.
     return false;
   }
 
   if (Shell::GetInstance()->GetAppListTargetVisibility())
     return true;
 
   // Unless |target| is in the full screen state, handle reserved accelerators
   // such as Alt+Tab now.
   return Shell::GetInstance()->accelerator_controller()->IsReservedAccelerator(
       accelerator);
 }
 
-bool AcceleratorDelegate::ProcessAccelerator(
-    const ui::Accelerator& accelerator) {
-  return Shell::GetInstance()->accelerator_controller()->Process(accelerator);
-}
-
 }  // namespace ash