Make readpixels work on GrTextures

include/gpu/GrContext.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 GrContext_DEFINED
 #define GrContext_DEFINED
 
@@ skipping 210 matching lines @@
         kDontFlush_PixelOpsFlag = 0x1,
         /** Any surface writes should be flushed to the backend 3D API after the surface operation
             is complete */
         kFlushWrites_PixelOp = 0x2,
         /** The src for write or dst read is unpremultiplied. This is only respected if both the
             config src and dst configs are an RGBA/BGRA 8888 format. */
         kUnpremul_PixelOpsFlag  = 0x4,
     };
 
     /**
-     * Reads a rectangle of pixels from a render target.
-     * @param target        the render target to read from.
+     * Reads a rectangle of pixels from a surface.
+     * @param surface       the surface to read from.
      * @param left          left edge of the rectangle to read (inclusive)
      * @param top           top edge of the rectangle to read (inclusive)
      * @param width         width of rectangle to read in pixels.
      * @param height        height of rectangle to read in pixels.
      * @param config        the pixel config of the destination buffer
      * @param buffer        memory to read the rectangle into.
      * @param rowBytes      number of bytes bewtween consecutive rows. Zero means rows are tightly
      *                      packed.
      * @param pixelOpsFlags see PixelOpsFlags enum above.
      *
      * @return true if the read succeeded, false if not. The read can fail because of an unsupported
-     *         pixel config or because no render target is currently set and NULL was passed for
-     *         target.
+     *         pixel configs
      */
-    bool readRenderTargetPixels(GrRenderTarget* target,
-                                int left, int top, int width, int height,
-                                GrPixelConfig config, void* buffer,
-                                size_t rowBytes = 0,
-                                uint32_t pixelOpsFlags = 0);
+    bool readSurfacePixels(GrSurface* surface,
+                           int left, int top, int width, int height,
+                           GrPixelConfig config, void* buffer,
+                           size_t rowBytes = 0,
+                           uint32_t pixelOpsFlags = 0);
 
     /**
      * Writes a rectangle of pixels to a surface.
      * @param surface       the surface to write to.
      * @param left          left edge of the rectangle to write (inclusive)
      * @param top           top edge of the rectangle to write (inclusive)
      * @param width         width of rectangle to write in pixels.
      * @param height        height of rectangle to write in pixels.
      * @param config        the pixel config of the source buffer
      * @param buffer        memory to read pixels from
@@ skipping 194 matching lines @@
     /**
      * A callback similar to the above for use by the TextBlobCache
      * TODO move textblob draw calls below context so we can use the call above.
      */
     static void TextBlobCacheOverBudgetCB(void* data);
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif