Merged op dispatch in OpReorderer

bug:22480459

Also switches std::functions to function pointers on OpReorderer, and
switches AssetAtlas' entry getter methods to using pixelRef pointers,
so it's clear they're the keys.

Change-Id: I3040ce5ff4e178a8364e0fd7ab0876ada7d4de05
diff --git a/libs/hwui/tests/common/TestUtils.h b/libs/hwui/tests/common/TestUtils.h
index 9c1c0b9d..0af9939 100644
--- a/libs/hwui/tests/common/TestUtils.h
+++ b/libs/hwui/tests/common/TestUtils.h
@@ -103,10 +103,11 @@
         return snapshot;
     }
 
-    static SkBitmap createSkBitmap(int width, int height) {
+    static SkBitmap createSkBitmap(int width, int height,
+            SkColorType colorType = kN32_SkColorType) {
         SkBitmap bitmap;
         SkImageInfo info = SkImageInfo::Make(width, height,
-                kN32_SkColorType, kPremul_SkAlphaType);
+                colorType, kPremul_SkAlphaType);
         bitmap.setInfo(info);
         bitmap.allocPixels(info);
         return bitmap;