From ca407201886875966db91d55c403fe0be3f0f4ca Mon Sep 17 00:00:00 2001
From: Tom Anderson <thomasanderson@chromium.org>
Date: Fri, 28 Jul 2017 00:32:42 +0000
Subject: [PATCH] Fix GTK2 build

R=erg@chromium.org

BUG=749770

Change-Id: If30b1d7e64998d78fb4e2635540ddfe922661391
Reviewed-on: https://chromium-review.googlesource.com/589826
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Elliot Glaysher <erg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490162}
---

diff --git a/chrome/browser/ui/libgtkui/gtk_ui.cc b/chrome/browser/ui/libgtkui/gtk_ui.cc
index a38c6b8..23f63b6 100644
--- a/chrome/browser/ui/libgtkui/gtk_ui.cc
+++ b/chrome/browser/ui/libgtkui/gtk_ui.cc
@@ -1052,11 +1052,20 @@
   if (display::Display::HasForceDeviceScaleFactor())
     return display::Display::GetForcedDeviceScaleFactor();
 
+#if GTK_MAJOR_VERSION == 2
+  GtkSettings* gtk_settings = gtk_settings_get_default();
+  gint gtk_dpi = -1;
+  g_object_get(gtk_settings, "gtk-xft-dpi", &gtk_dpi, nullptr);
+  const float scale_factor = gtk_dpi / (1024 * kDefaultDPI);
+#else
   GdkScreen* screen = gdk_screen_get_default();
   gint scale = gtk_widget_get_scale_factor(fake_window_);
+  DCHECK_GT(scale, 0);
   gdouble resolution = gdk_screen_get_resolution(screen);
   const float scale_factor =
       resolution <= 0 ? scale : resolution * scale / kDefaultDPI;
+#endif
+
   // Blacklist scaling factors <120% (crbug.com/484400) and round
   // to 1 decimal to prevent rendering problems (crbug.com/485183).
   return scale_factor < 1.2f ? 1.0f : roundf(scale_factor * 10) / 10;