Revert broken Linux hidpi changes.

chrome/browser/ui/libgtk2ui/gtk2_ui.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 "chrome/browser/ui/libgtk2ui/gtk2_ui.h"
 
 #include <math.h>
 #include <set>
 
 #include <pango/pango.h>
-#include <X11/Xlib.h>
-#include <gio/gio.h>
 
 #include "base/command_line.h"
 #include "base/debug/leak_annotations.h"
 #include "base/environment.h"
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/nix/mime_util_xdg.h"
 #include "base/nix/xdg_util.h"
 #include "base/stl_util.h"
 #include "base/strings/string_split.h"
@@ skipping 22 matching lines @@
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkShader.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/skbitmap_operations.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gfx/x/x11_types.h"

[stapelberg, 2015/08/07 10:38:22]

You might be able to remove the x11_types.h include, as it was added with
https://codereview.chromium.org/1136913005/diff/200001/chrome/browser/ui/libg...

[Michael Moss, 2015/08/07 16:45:40]

Done.

 #include "ui/native_theme/native_theme.h"
 #include "ui/resources/grit/ui_resources.h"
 #include "ui/views/controls/button/label_button.h"
 #include "ui/views/controls/button/label_button_border.h"
 #include "ui/views/linux_ui/window_button_order_observer.h"
 #include "ui/views/resources/grit/views_resources.h"
 
 #if defined(USE_GCONF)
 #include "chrome/browser/ui/libgtk2ui/gconf_listener.h"
 #endif
@@ skipping 311 matching lines @@
     LOG(WARNING) << "Unexpected gtk-xft-rgba \"" << rgba << "\"";
     params.subpixel_rendering = gfx::FontRenderParams::SUBPIXEL_RENDERING_NONE;
   }
 
   g_free(hint_style);
   g_free(rgba);
 
   return params;
 }
 
-double GetBaseDPI() {
-  XDisplay* xdisplay = gfx::GetXDisplay();
-  int xscreen = DefaultScreen(xdisplay);
-  return (DisplayHeight(xdisplay, xscreen) * 25.4) /
-         DisplayHeightMM(xdisplay, xscreen);
-}
-
-double GetFontDPI() {
+double GetDPI() {
   GtkSettings* gtk_settings = gtk_settings_get_default();
   CHECK(gtk_settings);
   gint gtk_dpi = -1;
   g_object_get(gtk_settings, "gtk-xft-dpi", &gtk_dpi, NULL);
 
   // GTK multiplies the DPI by 1024 before storing it.
-  return (gtk_dpi > 0) ? gtk_dpi / 1024.0 : GetBaseDPI();
+  return (gtk_dpi > 0) ? gtk_dpi / 1024.0 : 96.0;
 }
 
 // Queries GTK for its font DPI setting and returns the number of pixels in a
 // point.
 double GetPixelsInPoint(float device_scale_factor) {
-  double dpi = GetFontDPI();
+  double dpi = GetDPI();
 
   // Take device_scale_factor into account — if Chrome already scales the
   // entire UI up by 2x, we should not also scale up.
   dpi /= device_scale_factor;
 
   // There are 72 points in an inch.
   return dpi / 72.0;
 }
 
 views::LinuxUI::NonClientMiddleClickAction GetDefaultMiddleClickAction() {
   scoped_ptr<base::Environment> env(base::Environment::Create());
   switch (base::nix::GetDesktopEnvironment(env.get())) {
     case base::nix::DESKTOP_ENVIRONMENT_KDE4:
       // Starting with KDE 4.4, windows' titlebars can be dragged with the
       // middle mouse button to create tab groups. We don't support that in
       // Chrome, but at least avoid lowering windows in response to middle
       // clicks to avoid surprising users who expect the KDE behavior.
       return views::LinuxUI::MIDDLE_CLICK_ACTION_NONE;
     default:
       return views::LinuxUI::MIDDLE_CLICK_ACTION_LOWER;
   }
 }
 
-double GetGnomeTextScalingFactor() {
-  const char kDesktopInterfaceSchema[] = "org.gnome.desktop.interface";
-  for (const gchar* const* schemas = g_settings_list_schemas(); *schemas;
-       schemas++) {
-    if (!strcmp(kDesktopInterfaceSchema, static_cast<const char*>(*schemas))) {
-      GSettings* settings = g_settings_new(kDesktopInterfaceSchema);
-      double scale = g_settings_get_double(settings, "text-scaling-factor");
-      g_object_unref(settings);
-      return scale;
-    }
-  }
-  // Fallback if the schema does not exist.
-  return GetFontDPI() / GetBaseDPI();
-}
-
 }  // namespace
 
 Gtk2UI::Gtk2UI()
     : default_font_size_pixels_(0),
       default_font_style_(gfx::Font::NORMAL),
       middle_click_action_(GetDefaultMiddleClickAction()),
       device_scale_factor_(1.0) {
   GtkInitFromCommandLine(*base::CommandLine::ForCurrentProcess());
 }
 
@@ skipping 999 matching lines @@
 
 void Gtk2UI::UpdateDeviceScaleFactor(float device_scale_factor) {
   device_scale_factor_ = device_scale_factor;
   GtkStyle* label_style = gtk_rc_get_style(fake_label_.get());
   UpdateDefaultFont(label_style->font_desc);
 }
 
 float Gtk2UI::GetDeviceScaleFactor() const {
   if (gfx::Display::HasForceDeviceScaleFactor())
     return gfx::Display::GetForcedDeviceScaleFactor();
-  // Linux chrome does not support dynamnic scale factor change. Use the
-  // value obtanied during startup. The value is rounded to 1 decimal, e.g.
-  // to 1.4, for safety.
-  static float device_scale_factor =
-      roundf(GetGnomeTextScalingFactor() * 10) / 10;
-  return device_scale_factor;
+  const int kCSSDefaultDPI = 96;
+  float scale = GetDPI() / kCSSDefaultDPI;
+  // Round to 2 decimals, e.g. to 1.33.
+  return roundf(scale * 100) / 100;

[stapelberg, 2015/08/07 10:38:22]

I think we should keep the rounding to 1 decimal, i.e.

// Round to 1 decimal, e.g. to 1.4.
return roundf(scale * 10) / 10;

[Michael Moss, 2015/08/07 16:45:40]

Done.

 }
 
 }  // namespace libgtk2ui
 
 views::LinuxUI* BuildGtk2UI() {
   return new libgtk2ui::Gtk2UI;
 }