Do not playback existing commands for full deferred canvas writePixels

src/utils/SkDeferredCanvas.cpp

Index: src/utils/SkDeferredCanvas.cpp
diff --git a/src/utils/SkDeferredCanvas.cpp b/src/utils/SkDeferredCanvas.cpp
index 8fe9f8a4b59e5651fa3f057b42978fd9ef220fca..b95c040fff79c70f323d88a5c894e880142b820c 100644
--- a/src/utils/SkDeferredCanvas.cpp
+++ b/src/utils/SkDeferredCanvas.cpp
@@ -445,11 +445,11 @@ bool SkDeferredDevice::onWritePixels(const SkImageInfo& info, const void* pixels
     SkASSERT(x + info.width() <= width());
     SkASSERT(y + info.height() <= height());
 
-    this->flushPendingCommands(kNormal_PlaybackMode);
-
     const SkImageInfo deviceInfo = this->imageInfo();
     if (info.width() == deviceInfo.width() && info.height() == deviceInfo.height()) {
         this->skipPendingCommands();
+    } else {
+        this->flushPendingCommands(kNormal_PlaybackMode);
     }
 
     this->prepareForImmediatePixelWrite();