Mac: Disable loading 2x bitmaps on 10.5 and 10.6

ui/base/resource/resource_bundle_mac.mm

Index: ui/base/resource/resource_bundle_mac.mm
diff --git a/ui/base/resource/resource_bundle_mac.mm b/ui/base/resource/resource_bundle_mac.mm
index 2c66d6088b7ce350974ddf09f4515c9c5f563971..458f74aaa0ff097d757b097baa26096205a83888 100644
--- a/ui/base/resource/resource_bundle_mac.mm
+++ b/ui/base/resource/resource_bundle_mac.mm
@@ -11,6 +11,7 @@
 #include "base/mac/mac_util.h"
 #include "base/memory/scoped_nsobject.h"
 #include "base/synchronization/lock.h"
+#include "base/sys_info.h"
 #include "base/sys_string_conversions.h"
 #include "ui/gfx/image.h"
 
@@ -47,7 +48,16 @@ FilePath ResourceBundle::GetResourcesFilePath() {
 
 // static
 FilePath ResourceBundle::GetLargeIconResourcesFilePath() {
-  return GetResourcesPakFilePath(@"theme_resources_large", nil);
+  int32 major = 0;
+  int32 minor = 0;
+  int32 bugfix = 0;
+  base::SysInfo::OperatingSystemVersionNumbers(&major, &minor, &bugfix);
+
+  // Only load the large resource pak on if we're running on 10.7 or above.
+  if (major > 10 || (major == 10 && minor >= 7))
+    return GetResourcesPakFilePath(@"theme_resources_large", nil);
+  else
+    return FilePath();
 }
 
 // static