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

gpu/command_buffer/service/gles2_cmd_decoder_unittest.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 "gpu/command_buffer/service/gles2_cmd_decoder_unittest.h"
 
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
 #include "gpu/command_buffer/common/gles2_cmd_format.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
@@ skipping 447 matching lines @@
            kInvalidSharedMemoryOffset,
            kCount,
            kSharedMemoryId,
            kSharedMemoryOffset + kResultsOffset,
            result_size);
   EXPECT_EQ(error::kOutOfBounds, ExecuteCmd(cmd));
   EXPECT_EQ(GL_NO_ERROR, GetGLError());
   // Check bad count.
   cmd.Init(kSharedMemoryId,
            kSharedMemoryOffset + kPnameOffset,
-           -1,
+           static_cast<GLuint>(-1),
            kSharedMemoryId,
            kSharedMemoryOffset + kResultsOffset,
            result_size);
   EXPECT_EQ(error::kOutOfBounds, ExecuteCmd(cmd));
   EXPECT_EQ(GL_NO_ERROR, GetGLError());
   // Check bad results pointer.
   cmd.Init(kSharedMemoryId,
            kSharedMemoryOffset + kPnameOffset,
            kCount,
            kInvalidSharedMemoryId,
@@ skipping 847 matching lines @@
 INSTANTIATE_TEST_CASE_P(Service, GLES2DecoderWithShaderTest, ::testing::Bool());
 
 INSTANTIATE_TEST_CASE_P(Service, GLES2DecoderManualInitTest, ::testing::Bool());
 
 INSTANTIATE_TEST_CASE_P(Service,
                         GLES2DecoderRGBBackbufferTest,
                         ::testing::Bool());
 
 }  // namespace gles2
 }  // namespace gpu