Implement support for origin-TopLeft render targets. Note that the default behaviour remains the same:  textures default to origin-TopLeft, render targets default to origin-BottomLeft, and backend textures default to origin-BottomLeft. However, the caller can override the default by setting fOrigin in GrTextureDesc, GrBackendTextureDesc or GrBackendRenderTargetDesc.

Review URL: https://codereview.appspot.com/7230049

git-svn-id: http://skia.googlecode.com/svn/trunk@7594 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrGpu.cpp b/src/gpu/GrGpu.cpp
index 3da8219..47d4069 100644
--- a/src/gpu/GrGpu.cpp
+++ b/src/gpu/GrGpu.cpp
@@ -231,10 +231,10 @@
 bool GrGpu::readPixels(GrRenderTarget* target,
                        int left, int top, int width, int height,
                        GrPixelConfig config, void* buffer,
-                       size_t rowBytes, bool invertY) {
+                       size_t rowBytes) {
     this->handleDirtyContext();
     return this->onReadPixels(target, left, top, width, height,
-                              config, buffer, rowBytes, invertY);
+                              config, buffer, rowBytes);
 }
 
 void GrGpu::writeTexturePixels(GrTexture* texture,