Add the partial screen magnifier to Chrome OS.

ash/magnifier/magnification_controller.h

Index: ash/magnifier/magnification_controller.h
diff --git a/ash/magnifier/magnification_controller.h b/ash/magnifier/magnification_controller.h
index 4b0e86540c33fd6f1a67d7cc201c3e0f00b2e2ec..8f85d40137798dab1be551c9d7414f41b6da392b 100644
--- a/ash/magnifier/magnification_controller.h
+++ b/ash/magnifier/magnification_controller.h
@@ -30,6 +30,8 @@ class MagnificationController {
   // Enables (or disables if |enabled| is false) screen magnifier feature.
   virtual void SetEnabled(bool enabled) = 0;
 
+  virtual bool IsEnabled() = 0;

[oshima, 2012/09/13 16:35:31]

can this be const?

[Zachary Kuznia, 2012/10/09 09:02:36]

Done.

+
   // Sets the magnification ratio. 1.0f means no magnification.
   virtual void SetScale(float scale, bool animate) = 0;
   // Returns the current magnification ratio.