Add an origin flag for backend (external) textures.  Some textures in WebKit have a topdown orientation, and skia needs to be notified of this, so that they are not drawn upside-down.

Review URL: https://codereview.appspot.com/7200048

git-svn-id: http://skia.googlecode.com/svn/trunk@7414 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLRenderTarget.cpp b/src/gpu/gl/GrGLRenderTarget.cpp
index c68283e..47128e7 100644
--- a/src/gpu/gl/GrGLRenderTarget.cpp
+++ b/src/gpu/gl/GrGLRenderTarget.cpp
@@ -51,7 +51,7 @@
                          viewport.fWidth, viewport.fHeight,
                          desc.fConfig, desc.fSampleCnt),
                 texture->origin()) {
-    GrAssert(kBottomLeft_Origin == texture->origin());
+    GrAssert(kBottomLeft_GrSurfaceOrigin == texture->origin());
     GrAssert(NULL != texID);
     GrAssert(NULL != texture);
     // FBO 0 can't also be a texture, right?
@@ -74,7 +74,7 @@
                 MakeDesc(kNone_GrTextureFlags,
                          viewport.fWidth, viewport.fHeight,
                          desc.fConfig, desc.fSampleCnt),
-                kBottomLeft_Origin) {
+                kBottomLeft_GrSurfaceOrigin) {
     this->init(desc, viewport, NULL);
 }