Move gtk_settings_get_default() call to the UI thread.

BUG=19971

Review URL: http://codereview.chromium.org/173216

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@24034 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 33 insertions, 6 deletions

diff --git a/base/mime_util.h b/base/mime_util.h
index 4b67e46..7e1593b 100644
--- a/base/mime_util.h
+++ b/base/mime_util.h
@@ -20,6 +20,13 @@ std::string GetFileMimeType(const FilePath& filepath);
 // Get the mime type for a byte vector.
 std::string GetDataMimeType(const std::string& data);
 
+#if defined(OS_LINUX)
+// This detects the current GTK theme by calling gtk_settings_get_default().
+// It should only be executed on the UI thread and must be called before
+// GetMimeIcon().
+void DetectGtkTheme();
+#endif
+
 // Gets the file name for an icon given the mime type and icon pixel size.
 // Where an icon is a square image of |size| x |size|.
 // This will try to find the closest matching icon. If that's not available,
diff --git a/base/mime_util_linux.cc b/base/mime_util_linux.cc
index c5fe60c..b42122f 100644
--- a/base/mime_util_linux.cc
+++ b/base/mime_util_linux.cc
@@ -15,6 +15,7 @@
 
 #include "base/file_util.h"
 #include "base/logging.h"
+#include "base/message_loop.h"
 #include "base/scoped_ptr.h"
 #include "base/singleton.h"
 #include "base/string_util.h"
@@ -46,6 +47,11 @@ class MimeUtilConstants {
 
   time_t last_check_time_;
 
+  // This is set by DetectGtkTheme(). We cache it so that we can access the
+  // theme name from threads that aren't allowed to call
+  // gtk_settings_get_default().
+  std::string gtk_theme_name_;
+
  private:
   MimeUtilConstants()
       : kUpdateInterval(5),
@@ -489,13 +495,9 @@ void InitDefaultThemes() {
     default_themes[2] = IconTheme::LoadTheme(kde_fallback_theme);
   } else {
     // Assume it's Gnome and use GTK to figure out the theme.
-    gchar* gtk_theme_name;
-    g_object_get(gtk_settings_get_default(),
-                 "gtk-icon-theme-name",
-                 &gtk_theme_name, NULL);
-    default_themes[1] = IconTheme::LoadTheme(gtk_theme_name);
+    default_themes[1] = IconTheme::LoadTheme(
+        Singleton<MimeUtilConstants>::get()->gtk_theme_name_);
     default_themes[2] = IconTheme::LoadTheme("gnome");
-    g_free(gtk_theme_name);
   }
   // hicolor needs to be last per icon theme spec.
   default_themes[3] = IconTheme::LoadTheme("hicolor");
@@ -550,6 +552,24 @@ std::string GetDataMimeType(const std::string& data) {
   return xdg_mime_get_mime_type_for_data(data.data(), data.length(), NULL);
 }
 
+void DetectGtkTheme() {
+  // If the theme name is already loaded, do nothing. Chrome doesn't respond
+  // to changes in the system theme, so we never need to set this more than
+  // once.
+  if (!Singleton<MimeUtilConstants>::get()->gtk_theme_name_.empty())
+    return;
+
+  // We should only be called on the UI thread.
+  DCHECK_EQ(MessageLoop::TYPE_UI, MessageLoop::current()->type());
+
+  gchar* gtk_theme_name;
+  g_object_get(gtk_settings_get_default(),
+               "gtk-icon-theme-name",
+               &gtk_theme_name, NULL);
+  Singleton<MimeUtilConstants>::get()->gtk_theme_name_.assign(gtk_theme_name);
+  g_free(gtk_theme_name);
+}
+
 FilePath GetMimeIcon(const std::string& mime_type, size_t size) {
   std::vector<std::string> icon_names;
   std::string icon_name;