Disable layer hoisting for non-8888 canvases

src/core/SkMultiPictureDraw.cpp

Index: src/core/SkMultiPictureDraw.cpp
diff --git a/src/core/SkMultiPictureDraw.cpp b/src/core/SkMultiPictureDraw.cpp
index 26e446d2adaf463040607d4d5b5d116f6af273c2..40d93b1dd74a102f8659058dfd40b887a8362d03 100644
--- a/src/core/SkMultiPictureDraw.cpp
+++ b/src/core/SkMultiPictureDraw.cpp
@@ -124,7 +124,9 @@ void SkMultiPictureDraw::draw(bool flush) {
         // we only expect 1 context for all the canvases
         SkASSERT(data.fCanvas->getGrContext() == context);
 
-        if (!data.fPaint) {
+        if (!data.fPaint && 
+            (kRGBA_8888_SkColorType == data.fCanvas->imageInfo().colorType() ||
+             kBGRA_8888_SkColorType == data.fCanvas->imageInfo().colorType())) {
             SkRect clipBounds;
             if (!data.fCanvas->getClipBounds(&clipBounds)) {
                 continue;