Added pretty printers for some Ink Drop enums.

ui/views/animation/ink_drop_hover.h

Index: ui/views/animation/ink_drop_hover.h
diff --git a/ui/views/animation/ink_drop_hover.h b/ui/views/animation/ink_drop_hover.h
index b2dc69c95e6136e279d6090458b493f9ebcbfac0..4c18b1d1889970d3a84b009c3bffb4ac6c2da5cd 100644
--- a/ui/views/animation/ink_drop_hover.h
+++ b/ui/views/animation/ink_drop_hover.h
@@ -5,6 +5,7 @@
 #ifndef UI_VIEWS_ANIMATION_INK_DROP_HOVER_H_
 #define UI_VIEWS_ANIMATION_INK_DROP_HOVER_H_
 
+#include <iosfwd>
 #include <memory>
 
 #include "base/macros.h"
@@ -113,6 +114,14 @@ class VIEWS_EXPORT InkDropHover {
   DISALLOW_COPY_AND_ASSIGN(InkDropHover);
 };
 
+// Returns a human readable string for |animation_type|.  Useful for logging.
+VIEWS_EXPORT std::string ToString(InkDropHover::AnimationType animation_type);
+
+// This is declared here for use in gtest-based unit tests but is defined in
+// the views_test_support target. Depend on that to use this in your unit test.
+// This should not be used in production code - call ToString() instead.
+void PrintTo(InkDropHover::AnimationType animation_type, ::std::ostream* os);
+
 }  // namespace views
 
 #endif  // UI_VIEWS_ANIMATION_INK_DROP_HOVER_H_