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

ui/base/resource/resource_bundle_unittest.cc

Index: ui/base/resource/resource_bundle_unittest.cc
diff --git a/ui/base/resource/resource_bundle_unittest.cc b/ui/base/resource/resource_bundle_unittest.cc
index 488947dbc8f8be5bb1067e830662b3c5b900d624..4ed753c7a7fa41e798dbc7a48bfbd98ef2825e3a 100644
--- a/ui/base/resource/resource_bundle_unittest.cc
+++ b/ui/base/resource/resource_bundle_unittest.cc
@@ -19,13 +19,10 @@
 #include "ui/base/layout.h"
 #include "ui/base/resource/data_pack.h"
 #include "ui/gfx/codec/png_codec.h"
+#include "ui/gfx/dpi.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/resources/grit/ui_resources.h"
 
-#if defined(OS_WIN)
-#include "ui/gfx/win/dpi.h"
-#endif
-
 using ::testing::_;
 using ::testing::Between;
 using ::testing::Property;
@@ -472,7 +469,7 @@ TEST_F(ResourceBundleImageTest, GetRawDataResource) {
 // Test requesting image reps at various scale factors from the image returned
 // via ResourceBundle::GetImageNamed().
 TEST_F(ResourceBundleImageTest, GetImageNamed) {
-#if defined(OS_WIN)
+#if defined(OS_WIN) || (defined(OS_LINUX) && !defined(OS_CHROMEOS))
   gfx::ForceHighDPISupportForTesting(2.0);
 #endif
   std::vector<ScaleFactor> supported_factors;
@@ -495,7 +492,7 @@ TEST_F(ResourceBundleImageTest, GetImageNamed) {
 
   gfx::ImageSkia* image_skia = resource_bundle->GetImageSkiaNamed(3);
 
-#if defined(OS_CHROMEOS) || defined(OS_WIN)
+#if defined(OS_CHROMEOS) || defined(OS_WIN) || defined(OS_LINUX)
   // ChromeOS/Windows load highest scale factor first.
   EXPECT_EQ(ui::SCALE_FACTOR_200P,
             GetSupportedScaleFactor(image_skia->image_reps()[0].scale()));