rename SkDrawable to SkADrawable

BUG=skia:

Review URL: https://codereview.chromium.org/764463002
diff --git a/src/animator/SkDisplayEvents.cpp b/src/animator/SkDisplayEvents.cpp
index c42fbdf..3c3791d 100644
--- a/src/animator/SkDisplayEvents.cpp
+++ b/src/animator/SkDisplayEvents.cpp
@@ -12,7 +12,7 @@
 #include "SkAnimator.h"
 #include "SkDisplayEvent.h"
 #include "SkDisplayMovie.h"
-#include "SkDrawable.h"
+#include "SkADrawable.h"
 #ifdef SK_DEBUG
 #include "SkDump.h"
 #endif
@@ -82,7 +82,7 @@
     SkTDDrawableArray& drawArray = maker.fDisplayList.fDrawList;
     int count = drawArray.count();
     for (index = 0; index < count; index++) {
-        SkDrawable* drawable = drawArray[index];
+        SkADrawable* drawable = drawArray[index];
         drawable->dumpEvents();
     }
     count = fEvents.count();