Move SkGLContext and some GrGLInterface implementations to skgputest module

tests/ImageTest.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <functional>
 #include <initializer_list>
 #include "DMGpuSupport.h"
 
 #include "SkAutoPixmapStorage.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkDevice.h"
 #include "SkImageEncoder.h"
 #include "SkImageGenerator.h"
 #include "SkImage_Base.h"
 #include "SkPicture.h"
 #include "SkPictureRecorder.h"
 #include "SkPixelSerializer.h"
 #include "SkRRect.h"
 #include "SkStream.h"
 #include "SkSurface.h"
 #include "SkUtils.h"
 #include "Test.h"
 
+using sk_gpu_test::GrContextFactory;
+
 static void assert_equal(skiatest::Reporter* reporter, SkImage* a, const SkIRect* subsetA,
                          SkImage* b) {
     const int widthA = subsetA ? subsetA->width() : a->width();
     const int heightA = subsetA ? subsetA->height() : a->height();
 
     REPORTER_ASSERT(reporter, widthA == b->width());
     REPORTER_ASSERT(reporter, heightA == b->height());
 
     // see https://bug.skia.org/3965
     //REPORTER_ASSERT(reporter, a->isOpaque() == b->isOpaque());
@@ skipping 844 matching lines @@
                         otherContextInfo.fGrContext, buffer, budgeted));
                     REPORTER_ASSERT(reporter, !newImage2);
                     glContext->makeCurrent();
                 }
             }
             sk_free(buffer);
         }
     }
 }
 #endif