Fix Pango font rendering with HiDPi displays on Linux.

chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc

Index: chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc
diff --git a/chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc b/chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc
index be88def671a2eb3ece74927740a26b7915ed1424..b156de3192394545764adb7782887a198755a0ca 100644
--- a/chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc
+++ b/chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc
@@ -123,8 +123,13 @@ void ChromeBrowserMainExtraPartsAura::PreCreateThreads() {
   if (!chrome::ShouldOpenAshOnStartup())
 #endif
   {

[Daniel Erat, 2015/03/16 13:57:53]

the code that creates LinuxUI in
chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc looks like it's
hidden behind this:

#if defined(USE_X11) && !defined(OS_CHROMEOS)
  if (GetInitialDesktop() != chrome::HOST_DESKTOP_TYPE_ASH) {

this is already behind !OS_CHROMEOS, but it seems like you should have the rest
of it here.

[stapelberg, 2015/03/17 08:36:33]

Done.

-    gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE,
-                                   views::CreateDesktopScreen());
+    gfx::Screen* screen = views::CreateDesktopScreen();
+    gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE, screen);
+    views::LinuxUI *gtk2_ui = views::LinuxUI::instance();

[Daniel Erat, 2015/03/16 13:57:53]

nit: '*' goes to left of space

[stapelberg, 2015/03/17 08:36:33]

Done.

+    CHECK(gtk2_ui);

[Daniel Erat, 2015/03/16 13:57:53]

i'd just inline the views::LinuxUI::instance() where you use it below to keep
the code simpler; it doesn't look like this should ever be null.

[stapelberg, 2015/03/17 08:36:33]

Done.

+    gfx::Display display = screen->GetPrimaryDisplay();
+    CHECK(display.is_valid());

[Daniel Erat, 2015/03/16 13:57:53]

i don't see how it can ever be invalid.

[stapelberg, 2015/03/17 08:36:33]

Done.

+    gtk2_ui->UpdateDeviceScaleFactor(display.device_scale_factor());
   }
 #endif
 }