Cache render targets that render to wrapped textures

src/gpu/GrResourceProvider.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrResourceProvider.h"
 
 #include "GrBuffer.h"
@@ skipping 172 matching lines @@
         }
     }
     return rt->renderTargetPriv().getStencilAttachment();
 }
 
 GrRenderTarget* GrResourceProvider::wrapBackendTextureAsRenderTarget(
         const GrBackendTextureDesc& desc) {
     if (this->isAbandoned()) {
         return nullptr;
     }
+
+    GrUniqueKey key;
+    this->gpu()->computeBackendTextureKeyForWrapAsRenderTarget(desc, &key);
+    if (key.isValid()) {
+        sk_sp<GrRenderTarget> rt(this->findAndRefRenderTargetByUniqueKey(key));
+        if (rt && this->gpu()->rewrapRenderTargetWithBackendTexture(desc, rt.get())) {
+            return rt.release();
+        }
+    }
     return this->gpu()->wrapBackendTextureAsRenderTarget(desc);
 }