clang/win: Let remaining chromium_code targets build with -Wextra.

ui/gfx/screen_win_unittest.cc

 // Copyright 2015 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 "ui/gfx/screen_win.h"
 
 #include <cwchar>
 #include <string>
 #include <vector>
 
@@ skipping 38 matching lines @@
 };
 
 TEST_F(ScreenWinTest, SingleDisplay1x) {
   std::vector<MONITORINFOEX> monitor_infos;
   monitor_infos.push_back(CreateMonitorInfo(gfx::Rect(0, 0, 1920, 1200),
                                             gfx::Rect(0, 0, 1920, 1100),
                                             L"primary"));
   std::vector<gfx::Display> displays =
       ScreenWin::GetDisplaysForMonitorInfos(monitor_infos);
 
-  ASSERT_EQ(1, displays.size());
+  ASSERT_EQ(1u, displays.size());
   EXPECT_EQ(gfx::Rect(0, 0, 1920, 1200), displays[0].bounds());
   EXPECT_EQ(gfx::Rect(0, 0, 1920, 1100), displays[0].work_area());
 }
 
 TEST_F(ScreenWinTest, SingleDisplay2x) {
   gfx::InitDeviceScaleFactor(2.0);
 
   std::vector<MONITORINFOEX> monitor_infos;
   monitor_infos.push_back(CreateMonitorInfo(gfx::Rect(0, 0, 1920, 1200),
                                             gfx::Rect(0, 0, 1920, 1100),
                                             L"primary"));
   std::vector<gfx::Display> displays =
       ScreenWin::GetDisplaysForMonitorInfos(monitor_infos);
 
-  ASSERT_EQ(1, displays.size());
+  ASSERT_EQ(1u, displays.size());
   EXPECT_EQ(gfx::Rect(0, 0, 960, 600), displays[0].bounds());
   EXPECT_EQ(gfx::Rect(0, 0, 960, 550), displays[0].work_area());
 }
 
 }  // namespace gfx