Cache render targets that render to wrapped textures

src/gpu/GrTextureProvider.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 "GrTextureProvider.h"
 #include "GrTexturePriv.h"
 #include "GrResourceCache.h"
@@ skipping 181 matching lines @@
 GrTexture* GrTextureProvider::findAndRefTextureByUniqueKey(const GrUniqueKey& key) {
     ASSERT_SINGLE_OWNER
     GrGpuResource* resource = this->findAndRefResourceByUniqueKey(key);
     if (resource) {
         GrTexture* texture = static_cast<GrSurface*>(resource)->asTexture();
         SkASSERT(texture);
         return texture;
     }
     return NULL;
 }
+
+GrRenderTarget* GrTextureProvider::findAndRefRenderTargetByUniqueKey(const GrUniqueKey& key) {
+    ASSERT_SINGLE_OWNER
+    GrGpuResource* resource = this->findAndRefResourceByUniqueKey(key);
+    if (resource) {
+        GrRenderTarget* rt = static_cast<GrSurface*>(resource)->asRenderTarget();
+        SkASSERT(rt);
+        return rt;
+    }
+    return nullptr;
+}