Various optimizations to reduce the number of temporary allocations.

chrome/browser/themes/browser_theme_pack.h

Index: chrome/browser/themes/browser_theme_pack.h
diff --git a/chrome/browser/themes/browser_theme_pack.h b/chrome/browser/themes/browser_theme_pack.h
index effba56c166599aab5ef5163127d2d172eaf5c25..a5a347ddfb470ceb2d90c82a8980fd5c061d4abd 100644
--- a/chrome/browser/themes/browser_theme_pack.h
+++ b/chrome/browser/themes/browser_theme_pack.h
@@ -71,6 +71,9 @@ class BrowserThemePack : public CustomThemeSupplier {
   // theme.
   static void GetThemeableImageIDRs(std::set<int>* result);
 
+  // Returns true if an IDR exists.
+  static bool FindThemeableImageIDRs(int id);
+
   // Builds a data pack on disk at |path| for future quick loading by
   // BuildFromDataPack(). Often (but not always) called from the file thread;
   // implementation should be threadsafe because neither thread will write to