A11y: Introduce High Contrast Mode and Screen Magnifier to ubar tray.

ash/shell_delegate.h

Index: ash/shell_delegate.h
diff --git a/ash/shell_delegate.h b/ash/shell_delegate.h
index 7a94be4b377353e5700954b5e6f9fff78818a075..2b067d745bb36306cac108a570313ad0b5ac2955 100644
--- a/ash/shell_delegate.h
+++ b/ash/shell_delegate.h
@@ -8,6 +8,7 @@
 #include <vector>
 
 #include "ash/ash_export.h"
+#include "ash/magnifier/magnifier_constants.h"
 #include "ash/shell.h"
 #include "base/callback.h"
 #include "base/string16.h"
@@ -129,13 +130,28 @@ class ASH_EXPORT ShellDelegate {
   // Get the current browser context. This will get us the current profile.
   virtual content::BrowserContext* GetCurrentBrowserContext() = 0;
 
-  // Invoked when the user presses a shortcut to toggle spoken feedback
-  // for accessibility.
+  // Invoked to toggle spoken feedback for accessibility
   virtual void ToggleSpokenFeedback() = 0;
 
   // Returns true if spoken feedback is enabled.
   virtual bool IsSpokenFeedbackEnabled() const = 0;
 
+  // Invoked to toggle high contrast for accessibility.
+  virtual void ToggleHighContrast() = 0;
+
+  // Returns true if high contrast mode is enabled.
+  virtual bool IsHighContrastEnabled() const = 0;
+
+  // Invoked to change the mode of the screen magnifier.
+  virtual void SetMagnifier(MagnifierType type) = 0;
+
+  // Returns the current screen magnifier mode.
+  virtual MagnifierType GetMagnifierType() const = 0;
+
+  // Returns true if the user want to show accesibility menu even when all the
+  // accessibility features are disabled.
+  virtual bool ShouldAlwaysShowAccessibilityMenu() const = 0;
+
   // Invoked to create an AppListViewDelegate. Shell takes the ownership of
   // the created delegate.
   virtual app_list::AppListViewDelegate* CreateAppListViewDelegate() = 0;