Fixes for re-enabling more MSVC level 4 warnings: ppapi/ edition

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 548 matching lines @@
   pp::Graphics2D dc(instance_, pp::Size(w, h), false);
   ASSERT_FALSE(dc.is_null());
 
   // Replacing with a different size image should fail.
   pp::ImageData weird_size(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                            pp::Size(w - 1, h), true);
   ASSERT_FALSE(weird_size.is_null());
   dc.ReplaceContents(&weird_size);
 
   // Fill the background with blue but don't flush yet.
-  const int32_t background_color = 0xFF0000FF;
+  const uint32_t background_color = 0xFF0000FF;
   pp::ImageData background(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                            pp::Size(w, h), true);
   ASSERT_FALSE(background.is_null());
   FillRectInImage(&background, pp::Rect(0, 0, w, h), background_color);
   dc.PaintImageData(background, pp::Point(0, 0));
 
   // Replace with a green background but don't flush yet.
   const int32_t swapped_color = 0x00FF00FF;
   pp::ImageData swapped(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                         pp::Size(w, h), true);
@@ skipping 216 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();
 }