Revert of Move copy-surface-as-draw fallback to GrGLGpu.

src/gpu/GrDrawTarget.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawTarget_DEFINED
 #define GrDrawTarget_DEFINED
 
@@ skipping 160 matching lines @@
      */
     void saveActiveTraceMarkers();
     void restoreActiveTraceMarkers();
 
     /**
      * Copies a pixel rectangle from one surface to another. This call may finalize
      * reserved vertex/index data (as though a draw call was made). The src pixels
      * copied are specified by srcRect. They are copied to a rect of the same
      * size in dst with top left at dstPoint. If the src rect is clipped by the
      * src bounds then  pixel values in the dst rect corresponding to area clipped
-     * by the src rect are not overwritten. This method is not guaranteed to succeed
+     * by the src rect are not overwritten. This method can fail and return false
      * depending on the type of surface, configs, etc, and the backend-specific
-     * limitations.
+     * limitations. If rect is clipped out entirely by the src or dst bounds then
+     * true is returned since there is no actual copy necessary to succeed.
      */
-    void copySurface(GrSurface* dst,
+    bool copySurface(GrSurface* dst,
                      GrSurface* src,
                      const SkIRect& srcRect,
                      const SkIPoint& dstPoint);
     /**
+     * Function that determines whether a copySurface call would succeed without actually
+     * performing the copy.
+     */
+    bool canCopySurface(const GrSurface* dst,
+                        const GrSurface* src,
+                        const SkIRect& srcRect,
+                        const SkIPoint& dstPoint);
+
+    /**
      * Release any resources that are cached but not currently in use. This
      * is intended to give an application some recourse when resources are low.
      */
     virtual void purgeResources() {};
 
     ///////////////////////////////////////////////////////////////////////////
     // Draw execution tracking (for font atlases and other resources)
     class DrawToken {
     public:
         DrawToken(GrDrawTarget* drawTarget, uint32_t drawID) :
@@ skipping 168 matching lines @@
     virtual bool setupClip(GrPipelineBuilder*,
                            GrPipelineBuilder::AutoRestoreFragmentProcessors*,
                            GrPipelineBuilder::AutoRestoreStencil*,
                            GrScissorState* scissorState,
                            const SkRect* devBounds) override;
 
     typedef GrDrawTarget INHERITED;
 };
 
 #endif