Invalidate GrTexture mipmap on content change notification

src/gpu/SkGrPixelRef.cpp

Index: src/gpu/SkGrPixelRef.cpp
diff --git a/src/gpu/SkGrPixelRef.cpp b/src/gpu/SkGrPixelRef.cpp
index 3fa049166b7af588cbf8ec9a04d3b0e718d50ee4..ad6e24aa6f4e7643df779a376728fcc08de63b65 100644
--- a/src/gpu/SkGrPixelRef.cpp
+++ b/src/gpu/SkGrPixelRef.cpp
@@ -12,6 +12,7 @@
 
 #include "GrContext.h"
 #include "GrTexture.h"
+#include "GrTexturePriv.h"
 #include "SkBitmapCache.h"
 #include "SkGr.h"
 #include "SkRect.h"
@@ -126,6 +127,13 @@ GrTexture* SkGrPixelRef::getTexture() {
     return NULL;
 }
 
+void SkGrPixelRef::onNotifyPixelsChanged() {
+    GrTexture* texture = this->getTexture();
+    if (texture) {
+        texture->texturePriv().dirtyMipMaps(true);
+    }
+}
+
 SkPixelRef* SkGrPixelRef::deepCopy(SkColorType dstCT, SkColorProfileType dstPT,
                                    const SkIRect* subset) {
     if (NULL == fSurface) {