Don't issue texture barriers for RT's with separate storage

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLGpu.h"
 #include "GrGLStencilAttachment.h"
@@ skipping 2769 matching lines @@
             if(!SkIRect::IntersectsNoEmptyCheck(dstRect, srcRect)) {
                 return true;
             }
         } else {
             return true;
         }
     }
     return false;
 }
 
-void GrGLGpu::xferBarrier(GrXferBarrierType type) {
+void GrGLGpu::xferBarrier(GrRenderTarget* rt, GrXferBarrierType type) {
     switch (type) {
-        case kTexture_GrXferBarrierType:
+        case kTexture_GrXferBarrierType: {
+            GrGLRenderTarget* glrt = static_cast<GrGLRenderTarget*>(rt);
+            if (glrt->textureFBOID() != glrt->renderFBOID()) {
+                // The render target uses separate storage so no need for glTextureBarrier.
+                // FIXME: The render target will resolve automatically when its texture is bound,
+                // but we could resolve only the bounds that will be read if we do it here instead.
+                return;
+            }
             SkASSERT(this->caps()->textureBarrierSupport());
             GL_CALL(TextureBarrier());
             return;
+        }
         case kBlend_GrXferBarrierType:
             SkASSERT(GrDrawTargetCaps::kAdvanced_BlendEquationSupport ==
                      this->caps()->blendEquationSupport());
             GL_CALL(BlendBarrier());
             return;
     }
 }
 
 void GrGLGpu::didAddGpuTraceMarker() {
     if (this->caps()->gpuTracingSupport()) {
@@ skipping 42 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }