GrContext::copyTexture->GrContext::copySurface. Add a flush writes pixel ops flag.

include/gpu/GrContext.h

Index: include/gpu/GrContext.h
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index 366fba993e7dadecef4fe6e46352edfb64c62c73..4500936b82076d19210207409338f627854e9d77 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -597,12 +597,15 @@ public:
     * These flags can be used with the read/write pixels functions below.
     */
     enum PixelOpsFlags {
-        /** The GrContext will not be flushed. This means that the read or write may occur before
-            previous draws have executed. */
+        /** The GrContext will not be flushed before the surface read or write. This means that
+            the read or write may occur before previous draws have executed. */
         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  = 0x2,
+        kUnpremul_PixelOpsFlag  = 0x4,
     };
 
     /**
@@ -695,15 +698,36 @@ public:
                             uint32_t pixelOpsFlags = 0);
 
     /**
-     * Copies a rectangle of texels from src to dst. The size of dst is the size of the rectangle
-     * copied and topLeft is the position of the rect in src. The rectangle is clipped to src's
+     * Copies a rectangle of texels from src to dst.
      * bounds.
-     * @param src           the texture to copy from.
-     * @param dst           the render target to copy to.
-     * @param topLeft       the point in src that will be copied to the top-left of dst. If NULL,
-     *                      (0, 0) will be used.
+     * @param dst           the surface to copy to.
+     * @param src           the surface to copy from.
+     * @param srcRect       the rectangle of the src that should be copied.
+     * @param dstPoint      the translation applied when writing the srcRect's pixels to the dst.
+     * @param pixelOpsFlags see PixelOpsFlags enum above. (kUnpremul_PixelOpsFlag is not allowed).
      */
-    void copyTexture(GrTexture* src, GrRenderTarget* dst, const SkIPoint* topLeft = NULL);
+    void copySurface(GrSurface* dst,
+                     GrSurface* src,
+                     const SkIRect& srcRect,
+                     const SkIPoint& dstPoint,
+                     uint32_t pixelOpsFlags = 0);
+
+    /** Helper that copies the whole surface but fails when the two surfaces are not identically
+        sized. */
+    bool copySurface(GrSurface* dst, GrSurface* src) {
+        if (NULL == dst || NULL == src || dst->width() != src->width() ||
+            dst->height() != src->height()) {
+            return false;
+        }
+        this->copySurface(dst, src, SkIRect::MakeWH(dst->width(), dst->height()),
+                          SkIPoint::Make(0,0));
+        return true;
+    }
+
+    /**
+     * After this returns any pending writes to the surface will have been issued to the backend 3D API.
+     */
+    void flushSurfaceWrites(GrSurface* surface);
 
     /**
      * Resolves a render target that has MSAA. The intermediate MSAA buffer is