Verify that the image is not empty before calling memset().

ppapi/tests/test_graphics_2d.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/tests/test_graphics_2d.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 #include <set>
@@ skipping 303 matching lines @@
 std::string TestGraphics2D::TestInitToZero() {
   const int w = 15, h = 17;
   pp::Graphics2D dc(instance_, pp::Size(w, h), false);
   ASSERT_FALSE(dc.is_null());
 
   // Make an image with nonzero data in it (so we can test that zeros were
   // actually read versus ReadImageData being a NOP).
   pp::ImageData image(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                       pp::Size(w, h), true);
   ASSERT_FALSE(image.is_null());
+  ASSERT_FALSE(image.size().IsEmpty());
   memset(image.data(), 0xFF, image.stride() * image.size().height() * 4);
 
   // Read out the initial data from the device & check.
   ASSERT_TRUE(ReadImageData(dc, &image, pp::Point(0, 0)));
   ASSERT_TRUE(IsSquareInImage(image, 0, pp::Rect(0, 0, w, h), 0));
 
   PASS();
 }
 
 std::string TestGraphics2D::TestDescribe() {
@@ skipping 473 matching lines @@
   pp::Graphics2D dc(instance_, pp::Size(w, h), false);
   ASSERT_FALSE(dc.is_null());
   ASSERT_TRUE(instance_->BindGraphics(dc));
 
   ASSERT_TRUE(instance_->BindGraphics(pp::Graphics2D()));
   ASSERT_TRUE(instance_->BindGraphics(pp::Graphics3D()));
 
   PASS();
 }