linux_aura: Enable HIDPI support

ui/base/resource/resource_bundle.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 "ui/base/resource/resource_bundle.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 555 matching lines @@
   // Have high-DPI resources for 140% and 180% scaling on Windows based on
   // default scaling for Metro mode.  Round to nearest supported scale in
   // all cases.
   if (gfx::IsInHighDPIMode()) {
     supported_scale_factors.push_back(SCALE_FACTOR_140P);
     supported_scale_factors.push_back(SCALE_FACTOR_180P);
   }
 #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)
   // Must be called _after_ supported scale factors are set since it
   // uses them.
   ui::win::InitDeviceScaleFactor();
 #endif
 }
 
 void ResourceBundle::FreeImages() {
@@ skipping 218 matching lines @@
 // static
 bool ResourceBundle::DecodePNG(const unsigned char* buf,
                                size_t size,
                                SkBitmap* bitmap,
                                bool* fell_back_to_1x) {
   *fell_back_to_1x = PNGContainsFallbackMarker(buf, size);
   return gfx::PNGCodec::Decode(buf, size, bitmap);
 }
 
 }  // namespace ui