aura: Make the Linux version of IconLoader not require GTK+.

base/mime_util_xdg.cc

Index: base/mime_util_xdg.cc
diff --git a/base/mime_util_xdg.cc b/base/mime_util_xdg.cc
index fcd8d97576c802a60adf9050513383ca21434c0e..efe64b39d47004c0bfa00cfb55314cdcc5c238f3 100644
--- a/base/mime_util_xdg.cc
+++ b/base/mime_util_xdg.cc
@@ -4,7 +4,6 @@
 
 #include "base/mime_util.h"
 
-#include <gtk/gtk.h>
 #include <sys/time.h>
 #include <time.h>
 
@@ -27,6 +26,10 @@
 #include "base/third_party/xdg_mime/xdgmime.h"
 #include "base/threading/thread_restrictions.h"
 
+#if defined(TOOLKIT_USES_GTK)
+#include <gtk/gtk.h>
+#endif
+
 namespace {
 
 // None of the XDG stuff is thread-safe, so serialize all access under
@@ -66,10 +69,12 @@ class MimeUtilConstants {
 
   time_t last_check_time_;
 
+#if defined(TOOLKIT_USES_GTK)
   // 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_;
+#endif
 
  private:
   MimeUtilConstants()
@@ -507,10 +512,12 @@ void InitDefaultThemes() {
     default_themes[1] = IconTheme::LoadTheme(kde_default_theme);
     default_themes[2] = IconTheme::LoadTheme(kde_fallback_theme);
   } else {
+#if defined(TOOLKIT_USES_GTK)
     // Assume it's Gnome and use GTK to figure out the theme.
     default_themes[1] = IconTheme::LoadTheme(
         MimeUtilConstants::GetInstance()->gtk_theme_name_);
     default_themes[2] = IconTheme::LoadTheme("gnome");
+#endif
   }
   // hicolor needs to be last per icon theme spec.
   default_themes[3] = IconTheme::LoadTheme("hicolor");
@@ -567,6 +574,7 @@ std::string GetDataMimeType(const std::string& data) {
   return xdg_mime_get_mime_type_for_data(data.data(), data.length(), NULL);
 }
 
+#if defined(TOOLKIT_USES_GTK)
 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
@@ -584,6 +592,7 @@ void DetectGtkTheme() {
   MimeUtilConstants::GetInstance()->gtk_theme_name_.assign(gtk_theme_name);
   g_free(gtk_theme_name);
 }
+#endif
 
 FilePath GetMimeIcon(const std::string& mime_type, size_t size) {
   base::ThreadRestrictions::AssertIOAllowed();