Revert of Return GrGLContext from GrTestTarget

tests/SurfaceTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkDevice.h"
@@ skipping 97 matching lines @@
     }
 
     GrTestTarget tt;
     ctx->getTestTarget(&tt);
     if (!tt.target()) {
         SkDEBUGFAIL("Couldn't get Gr test target.");
         return;
     }
 
     // We currently have only implemented the texture uploads for GL.
-    const GrGLInterface* gl = tt.glContext()->interface();
+    const GrGLInterface* gl = tt.glInterface();
     if (!gl) {
         return;
     }
 
     // Test the wrapped factory for SkSurface by creating a texture using GL and then wrap it in
     // a SkSurface.
     GrGLuint texID;
     static const int kW = 100;
     static const int kH = 100;
     static const uint32_t kOrigColor = 0xFFAABBCC;
@@ skipping 762 matching lines @@
     // We expect the ref'd image to see the new color, but cpy'd one should still see the old color
     test_image_color(reporter, refImg, expected1);
     test_image_color(reporter, cpyImg, expected0);
 
     // Now exercise the release proc
     REPORTER_ASSERT(reporter, !releaseCtx.fIsReleased);
     refImg.reset(NULL); // force a release of the image
     REPORTER_ASSERT(reporter, releaseCtx.fIsReleased);
 }
 #endif