Fix valgrind uninitialized memory complaint

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 "SkRRect.h"
 #include "SkSurface.h"
@@ skipping 66 matching lines @@
     const SkPoint testPoints[3] = {
         {SkIntToScalar(0), SkIntToScalar(0)},
         {SkIntToScalar(2), SkIntToScalar(1)},
         {SkIntToScalar(0), SkIntToScalar(2)}
     };
     const size_t testPointCount = 3;
 
     SkBitmap testBitmap;
     testBitmap.setConfig(SkBitmap::kARGB_8888_Config, 10, 10);
     testBitmap.allocPixels();
+    testBitmap.eraseColor(0);
 
     SkRRect testRRect;
     testRRect.setRectXY(testRect, SK_Scalar1, SK_Scalar1);
 
     SkString testText("Hello World");
     const SkPoint testPoints2[] = {
         { SkIntToScalar(0), SkIntToScalar(1) },
         { SkIntToScalar(1), SkIntToScalar(1) },
         { SkIntToScalar(2), SkIntToScalar(1) },
         { SkIntToScalar(3), SkIntToScalar(1) },
@@ skipping 150 matching lines @@
         TestSurfaceWritableAfterSnapshotRelease(reporter, kGpu_SurfaceType, context);
         TestSurfaceNoCanvas(reporter, kGpu_SurfaceType, context, SkSurface::kDiscard_ContentChangeMode);
         TestSurfaceNoCanvas(reporter, kGpu_SurfaceType, context, SkSurface::kRetain_ContentChangeMode);
         TestGetTexture(reporter, kGpu_SurfaceType, context);
     }
 #endif
 }
 
 #include "TestClassDef.h"
 DEFINE_GPUTESTCLASS("Surface", SurfaceTestClass, TestSurface)