Corner Passthrough for Accessibility

chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc

 // Copyright 2013 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 "chrome/browser/ui/ash/chrome_shell_delegate.h"
 
 #include "ash/accelerators/magnifier_key_scroller.h"
 #include "ash/accelerators/spoken_feedback_toggler.h"
 #include "ash/accessibility_delegate.h"
 #include "ash/wm/mru_window_tracker.h"
@@ skipping 20 matching lines @@
 #include "chrome/browser/ui/ash/system_tray_delegate_chromeos.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/common/pref_names.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/ime/input_method_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/user_metrics.h"
 #include "grit/generated_resources.h"
+#include "media/audio/sounds/sounds_manager.h"
 #include "ui/aura/window.h"
 #include "ui/base/l10n/l10n_util.h"
 
 namespace {
 
 void InitAfterSessionStart() {
   // Restore focus after the user session is started.  It's needed because some
   // windows can be opened in background while login UI is still active because
   // we currently restore browser windows before login UI is deleted.
   ash::Shell* shell = ash::Shell::GetInstance();
@@ skipping 141 matching lines @@
         case ash::A11Y_ALERT_NONE:
           break;
       }
     }
   }
 
   virtual ash::AccessibilityAlert GetLastAccessibilityAlert() OVERRIDE {
     return ash::A11Y_ALERT_NONE;
   }
 
+  virtual void PlayEarcon(media::SoundsManager::SoundKey sound_key) OVERRIDE {
+    DCHECK(chromeos::AccessibilityManager::Get());

[James Cook, 2014/07/29 04:27:24]

We don't generally DCHECK something just before dereferencing it. If it's null,
the next line will just crash and it should be obvious why.

[dmazzoni, 2014/07/29 05:47:50]

I see that pattern a fair amount. Must be different conventions in different
parts of the code.

[James Cook, 2014/07/29 15:45:51]

Yeah. I use it as a way to establish preconditions for input to a function,
especially if that function is long:

void Foo(A* a, B* b) {
  DCHECK(a);  // precondition
  // No DCHECK(b) so it's probably OK to be NULL
  ...lots of code...
  a->DoSomething();
}

But I generally don't for things like:

void Foo(A* a, B* b) {
  a->DoSomething();  // Should be immediately obvious it can't be null
}

or

void Foo() {
  SomeAnnoyingSingleton::Get()->DoSomething();
}

That said, the rest of this file DCHECK's it, so in the interest of consistency,
keep the DCHECK.

[lisayin, 2014/07/30 15:32:51]

Acknowledged.

+    return chromeos::AccessibilityManager::Get()->PlayEarcon(sound_key);
+  }
+
   virtual base::TimeDelta PlayShutdownSound() const OVERRIDE {
     return chromeos::AccessibilityManager::Get()->PlayShutdownSound();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AccessibilityDelegateImpl);
 };
 
 }  // anonymous namespace
 
@@ skipping 63 matching lines @@
 }
 
 void ChromeShellDelegate::PlatformInit() {
   registrar_.Add(this,
                  chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  chrome::NOTIFICATION_SESSION_STARTED,
                  content::NotificationService::AllSources());
 }