Enable hidpi on Linux, refactor a bit on Windows to share

ui/base/test/run_all_unittests.cc

 // Copyright 2014 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 "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/path_service.h"
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
 #include "build/build_config.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
+#include "ui/gfx/dpi.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/jni_android.h"
 #include "ui/base/android/ui_base_jni_registrar.h"
 #include "ui/gfx/android/gfx_jni_registrar.h"
 #endif
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 #include "base/mac/bundle_locations.h"
 #include "base/test/mock_chrome_application_mac.h"
 #endif
 
-#if defined(OS_WIN)
-#include "ui/gfx/win/dpi.h"
-#endif
-
 namespace {
 
 class UIBaseTestSuite : public base::TestSuite {
  public:
   UIBaseTestSuite(int argc, char** argv);
 
  protected:
   // base::TestSuite:
   void Initialize() override;
   void Shutdown() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(UIBaseTestSuite);
 };
 
 UIBaseTestSuite::UIBaseTestSuite(int argc, char** argv)
     : base::TestSuite(argc, argv) {}
 
 void UIBaseTestSuite::Initialize() {
   base::TestSuite::Initialize();
 
-#if defined(OS_WIN)
+#if defined(OS_WIN) || (defined(OS_LINUX) && !defined(OS_CHROMEOS))
   gfx::ForceHighDPISupportForTesting(1.0);
 #endif
 
 #if defined(OS_ANDROID)
   // Register JNI bindings for android.
   gfx::android::RegisterJni(base::android::AttachCurrentThread());
   ui::android::RegisterJni(base::android::AttachCurrentThread());
 #endif
 
   ui::RegisterPathProvider();
@@ skipping 42 matching lines @@
 }  // namespace
 
 int main(int argc, char** argv) {
   UIBaseTestSuite test_suite(argc, argv);
 
   return base::LaunchUnitTests(argc,
                                argv,
                                base::Bind(&UIBaseTestSuite::Run,
                                           base::Unretained(&test_suite)));
 }