Re-introduce the partial magnifier

chrome/browser/ui/ash/chrome_shell_delegate.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 "chrome/browser/ui/ash/chrome_shell_delegate.h"
 
 #include "ash/host/root_window_host_factory.h"
 #include "ash/launcher/launcher_types.h"
 #include "ash/magnifier/magnifier_constants.h"
 #include "ash/system/tray/system_tray_delegate.h"
@@ skipping 336 matching lines @@
 #endif
 }
 
 void ChromeShellDelegate::ToggleHighContrast() {
 #if defined(OS_CHROMEOS)
   bool enabled = chromeos::accessibility::IsHighContrastEnabled();
   chromeos::accessibility::EnableHighContrast(!enabled);
 #endif
 }
 
+bool ChromeShellDelegate::IsMagnifierEnabled() const {
+#if defined(OS_CHROMEOS)
+  DCHECK(chromeos::MagnificationManager::Get());
+  return chromeos::MagnificationManager::Get()->IsMagnifierEnabled();
+#else
+  return false;
+#endif
+}
+
 ash::MagnifierType ChromeShellDelegate::GetMagnifierType() const {
 #if defined(OS_CHROMEOS)
   DCHECK(chromeos::MagnificationManager::Get());
   return chromeos::MagnificationManager::Get()->GetMagnifierType();
 #else
   return ash::MAGNIFIER_OFF;
 #endif
 }
 
-void ChromeShellDelegate::SetMagnifier(ash::MagnifierType type) {
+void ChromeShellDelegate::SetMagnifier(bool enabled, ash::MagnifierType type) {
 #if defined(OS_CHROMEOS)
   DCHECK(chromeos::MagnificationManager::Get());
-  return chromeos::MagnificationManager::Get()->SetMagnifier(type);
+  return chromeos::MagnificationManager::Get()->SetMagnifier(enabled, type);
 #endif
 }
 
 bool ChromeShellDelegate::ShouldAlwaysShowAccessibilityMenu() const {
 #if defined(OS_CHROMEOS)
   if (!IsUserLoggedIn())
     return true;
 
   Profile* profile = ProfileManager::GetDefaultProfile();
   if (!profile)
@@ skipping 177 matching lines @@
       ash::Shell::GetInstance()->ShowLauncher();
       break;
     default:
       NOTREACHED() << "Unexpected notification " << type;
   }
 #else
   // MSVC++ warns about switch statements without any cases.
   NOTREACHED() << "Unexpected notification " << type;
 #endif
 }