linux: Use gtk-cursor-blink from GtkSettings to set the caret blink interval

chrome/common/gtk_util.cc

Index: chrome/common/gtk_util.cc
diff --git a/chrome/common/gtk_util.cc b/chrome/common/gtk_util.cc
index 37fb13e9165d48abcba6e316c624678e8969a172..d5e0885598fd7aba5239072efb2218c354a0770b 100644
--- a/chrome/common/gtk_util.cc
+++ b/chrome/common/gtk_util.cc
@@ -461,11 +461,19 @@ GtkWidget* IndentWidget(GtkWidget* content) {
 void UpdateGtkFontSettings(RendererPreferences* prefs) {
   DCHECK(prefs);
 
+  // From http://library.gnome.org/devel/gtk/unstable/GtkSettings.html, this is
+  // the default value for gtk-cursor-blink-time.
+  static const gint kGtkDefaultCursorBlinkTime = 1200;
+
+  gint cursor_blink_time = kGtkDefaultCursorBlinkTime;
+  gboolean cursor_blink = TRUE;
   gint antialias = 0;
   gint hinting = 0;
   gchar* hint_style = NULL;
   gchar* rgba_style = NULL;
   g_object_get(gtk_settings_get_default(),
+               "gtk-cursor-blink-time", &cursor_blink_time,
+               "gtk-cursor-blink", &cursor_blink,
                "gtk-xft-antialias", &antialias,
                "gtk-xft-hinting", &hinting,
                "gtk-xft-hintstyle", &hint_style,
@@ -478,6 +486,15 @@ void UpdateGtkFontSettings(RendererPreferences* prefs) {
   prefs->subpixel_rendering =
       RENDERER_PREFERENCES_SUBPIXEL_RENDERING_SYSTEM_DEFAULT;
 
+  if (cursor_blink) {
+    // Dividing by 2*1000ms follows the WebKit GTK port and makes the blink
+    // frequency appear similar to the omnibox.  Without this the blink is too
+    // slow.
+    prefs->caret_blink_interval = cursor_blink_time / 2000.;
+  } else {
+    prefs->caret_blink_interval = 0;
+  }
+
   // g_object_get() doesn't tell us whether the properties were present or not,
   // but if they aren't (because gnome-settings-daemon isn't running), we'll get
   // NULL values for the strings.