Re-introduce the partial magnifier

ash/magnifier/magnifier_constants.h

Index: ash/magnifier/magnifier_constants.h
diff --git a/ash/magnifier/magnifier_constants.h b/ash/magnifier/magnifier_constants.h
index 4ca4c892e97b3b01cd6f9e7039fa1e1906547a23..1626c5b73939694c66cc04c9c00619c9eeeedf1f 100644
--- a/ash/magnifier/magnifier_constants.h
+++ b/ash/magnifier/magnifier_constants.h
@@ -7,12 +7,17 @@
 
 namespace ash {
 
+// Note: Do not change these values; UMA and prefs depend on them.
 enum MagnifierType {
-  MAGNIFIER_OFF,
-  MAGNIFIER_FULL,
-  MAGNIFIER_PARTIAL,
+  MAGNIFIER_FULL    = 1,
+  MAGNIFIER_PARTIAL = 2,
 };
 
+// This value must be the maximum number of MagnifierType) + 1

[Daniel Erat, 2013/01/09 15:43:56]

s/)//

this is a bit misleading, though (it's 3, but there are only 2 types).  maybe
you could rename this to kMaxMagnifierType, set it to 2, and then just do
kMaxMagnifierType + 1 when recording the metric?

[yoshiki, 2013/01/10 06:25:39]

Done.

+const int kNumMagnifierTypes = 3;
+
+const MagnifierType kDefaultMagnifierType = MAGNIFIER_FULL;
+
 }  // namespace ash
 
 #endif  // ASH_MAGNIFIER_MAGNIFIER_CONSTANTS_H_