Fix GPU displacement with expanding crop rects.

src/effects/SkDisplacementMapEffect.cpp

Index: src/effects/SkDisplacementMapEffect.cpp
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index 4b26a5f846083f55de3e6707fcc9adf700ed9e7f..0200cabff85bf942a1b6d697d2e0370fd2672c6d 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -384,8 +384,8 @@ bool SkDisplacementMapEffect::filterImageGPU(Proxy* proxy, const SkBitmap& src,
 
     GrTextureDesc desc;
     desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
-    desc.fWidth = colorBM.width();
-    desc.fHeight = colorBM.height();
+    desc.fWidth = bounds.width();
+    desc.fHeight = bounds.height();
     desc.fConfig = kSkia8888_GrPixelConfig;
 
     GrAutoScratchTexture ast(context, desc);
@@ -410,6 +410,8 @@ bool SkDisplacementMapEffect::filterImageGPU(Proxy* proxy, const SkBitmap& src,
                                         color))->unref();
     SkIRect colorBounds = bounds;
     colorBounds.offset(-colorOffset);
+    GrContext::AutoMatrix am;
+    am.setIdentity(context);
     SkMatrix matrix;
     matrix.setTranslate(-SkIntToScalar(colorBounds.x()),
                         -SkIntToScalar(colorBounds.y()));