skia: Add support for CHROMIUM_image backed textures.

src/gpu/GrTexture.cpp

Index: src/gpu/GrTexture.cpp
diff --git a/src/gpu/GrTexture.cpp b/src/gpu/GrTexture.cpp
index 249fe98c20614eb52b631315104a2fb5f72bdf37..fe5b2c3c375d9b2131eb1ba1a43d39cea0d74f14 100644
--- a/src/gpu/GrTexture.cpp
+++ b/src/gpu/GrTexture.cpp
@@ -85,7 +85,8 @@ GrTexture::GrTexture(GrGpu* gpu, LifeCycle lifeCycle, const GrSurfaceDesc& desc)
     : INHERITED(gpu, lifeCycle, desc)
     , fMipMapsStatus(kNotAllocated_MipMapsStatus) {
 
-    if (!this->isExternal() && !GrPixelConfigIsCompressed(desc.fConfig)) {
+    if (!this->isExternal() && !GrPixelConfigIsCompressed(desc.fConfig) &&
+        !desc.fTextureStorageAllocator.fAllocateTextureStorage) {
         GrScratchKey key;
         GrTexturePriv::ComputeScratchKey(desc, &key);
         this->setScratchKey(key);