Use a struct for client GL texture handles

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 100 matching lines @@
         return;
     }
 
     // Test the wrapped factory for SkSurface by creating a backend texture and then wrap it in
     // a SkSurface.
     static const int kW = 100;
     static const int kH = 100;
     static const uint32_t kOrigColor = 0xFFAABBCC;
     SkAutoTArray<uint32_t> pixels(kW * kH);
     sk_memset32(pixels.get(), kOrigColor, kW * kH);
-    GrBackendObject texID = gpu->createTestingOnlyBackendTexture(pixels.get(), kW, kH,
-                                                                 kRGBA_8888_GrPixelConfig);
+    GrBackendObject texHandle = gpu->createTestingOnlyBackendTexture(pixels.get(), kW, kH,
+                                                                     kRGBA_8888_GrPixelConfig);
 
     GrBackendTextureDesc wrappedDesc;
     wrappedDesc.fConfig = kRGBA_8888_GrPixelConfig;
     wrappedDesc.fWidth = kW;
     wrappedDesc.fHeight = kH;
     wrappedDesc.fOrigin = kBottomLeft_GrSurfaceOrigin;
     wrappedDesc.fSampleCnt = 0;
     wrappedDesc.fFlags = kRenderTarget_GrBackendTextureFlag;
-    wrappedDesc.fTextureHandle = texID;
+    wrappedDesc.fTextureHandle = texHandle;
 
     SkAutoTUnref<SkSurface> surface(SkSurface::NewWrappedRenderTarget(ctx, wrappedDesc, nullptr));
     REPORTER_ASSERT(reporter, surface);
     if (surface) {
         // Validate that we can draw to the canvas and that the original texture color is preserved
         // in pixels that aren't rendered to via the surface.
         SkPaint paint;
         static const SkColor kRectColor = ~kOrigColor | 0xFF000000;
         paint.setColor(kRectColor);
         surface->getCanvas()->drawRect(SkRect::MakeWH(SkIntToScalar(kW), SkIntToScalar(kH)/2),
@@ skipping 880 matching lines @@
     test_image_color(reporter, refImg, expected1);
 #endif
     test_image_color(reporter, cpyImg, expected0);
 
     // Now exercise the release proc
     REPORTER_ASSERT(reporter, !releaseCtx.fIsReleased);
     refImg.reset(nullptr); // force a release of the image
     REPORTER_ASSERT(reporter, releaseCtx.fIsReleased);
 }
 #endif