linux_aura: Enable HIDPI support

ui/base/resource/resource_bundle.cc

Index: ui/base/resource/resource_bundle.cc
diff --git a/ui/base/resource/resource_bundle.cc b/ui/base/resource/resource_bundle.cc
index f9c5d6970969f3ae4926c1011d02a4eb816c1346..d9a42e28740deba5f69290639042b6ee94f8494e 100644
--- a/ui/base/resource/resource_bundle.cc
+++ b/ui/base/resource/resource_bundle.cc
@@ -573,6 +573,10 @@ void ResourceBundle::InitSharedInstance(Delegate* delegate) {
 #elif defined(OS_CHROMEOS)
   // TODO(oshima): Include 200P only if the device support 200P
   supported_scale_factors.push_back(SCALE_FACTOR_200P);
+#elif defined(OS_LINUX) && defined(USE_AURA)
+  // Provide same UX as on Win desktops.
+  supported_scale_factors.push_back(SCALE_FACTOR_140P);
+  supported_scale_factors.push_back(SCALE_FACTOR_180P);

[oshima, 2013/10/22 05:35:10]

FYI: These scale factors will use 200P assets with image scaling.

By the way, have to discuss this with anyone in UX team?
Certain part of UI uses different assets between Windows and Linux
and you need to make sure UX team is aware of it and produces the
right assets for linux high DPI as well.

[Elliot Glaysher, 2013/10/22 17:40:18]

IIRC, there are only a few assets that linux_aura uses that windows doesn't,
like the linux min/max/close buttons. You can find the 100P assets here:
ui/resources/default_100_percent/linux. I notice that there doesn't appear to be
200P versions of all those.

[Mikhail, 2013/10/23 17:15:02]

Should it be a stopper for this CL?

[Elliot Glaysher, 2013/10/23 17:51:19]

It shouldn't block the patch, but it should (possibly) block eventual release
for whatever you're doing. Upscaled resources look pretty bad, and I cringe when
I see obviously upscaled resources on my Pixel.

Make sure to file a bug to track this. CC it to me and I'll try to get the
designers to add 200P resources here.

[oshima, 2013/10/23 18:10:59]

sg

 #endif
   ui::SetSupportedScaleFactors(supported_scale_factors);
 #if defined(OS_WIN)