Use a struct for client GL texture handles

tests/GrSurfaceTest.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 "SkTypes.h"
 
 #if SK_SUPPORT_GPU
 
 #include "GrContext.h"
 #include "GrContextFactory.h"
+#include "GrGpu.h"
 #include "GrRenderTarget.h"
 #include "GrTexture.h"
 #include "GrSurfacePriv.h"
 #include "Test.h"
 
 // Tests that GrSurface::asTexture(), GrSurface::asRenderTarget(), and static upcasting of texture
 // and render targets to GrSurface all work as expected.
 DEF_GPUTEST(GrSurface, reporter, factory) {
     GrContext* context = factory->get(GrContextFactory::kNull_GLContextType);
     if (context) {
@@ skipping 13 matching lines @@
                                   static_cast<GrSurface*>(texRT1->asTexture()));
         REPORTER_ASSERT(reporter, static_cast<GrSurface*>(texRT1->asRenderTarget()) ==
                                   static_cast<GrSurface*>(texRT1->asTexture()));
 
         desc.fFlags = kNone_GrSurfaceFlags;
         GrSurface* tex1 = context->textureProvider()->createTexture(desc, false, nullptr, 0);
         REPORTER_ASSERT(reporter, nullptr == tex1->asRenderTarget());
         REPORTER_ASSERT(reporter, tex1 == tex1->asTexture());
         REPORTER_ASSERT(reporter, static_cast<GrSurface*>(tex1) == tex1->asTexture());
 
+        GrBackendObject backendTex = context->getGpu()->createTestingOnlyBackendTexture(
+            nullptr, 256, 256, kSkia8888_GrPixelConfig);
+
         GrBackendTextureDesc backendDesc;
         backendDesc.fConfig = kSkia8888_GrPixelConfig;
         backendDesc.fFlags = kRenderTarget_GrBackendTextureFlag;
         backendDesc.fWidth = 256;
         backendDesc.fHeight = 256;
         backendDesc.fSampleCnt = 0;
-        backendDesc.fTextureHandle = 5;
+        backendDesc.fTextureHandle = backendTex;
         GrSurface* texRT2 = context->textureProvider()->wrapBackendTexture(
             backendDesc, kBorrow_GrWrapOwnership);
         REPORTER_ASSERT(reporter, texRT2 == texRT2->asRenderTarget());
         REPORTER_ASSERT(reporter, texRT2 == texRT2->asTexture());
         REPORTER_ASSERT(reporter, static_cast<GrSurface*>(texRT2->asRenderTarget()) ==
                                   texRT2->asTexture());
         REPORTER_ASSERT(reporter, texRT2->asRenderTarget() ==
                                   static_cast<GrSurface*>(texRT2->asTexture()));
         REPORTER_ASSERT(reporter, static_cast<GrSurface*>(texRT2->asRenderTarget()) ==
-                                   static_cast<GrSurface*>(texRT2->asTexture()));
+                                  static_cast<GrSurface*>(texRT2->asTexture()));
 
         texRT1->unref();
         texRT2->unref();
         tex1->unref();
+        context->getGpu()->deleteTestingOnlyBackendTexture(backendTex);
     }
 }
 
 #endif