Add a new GetInstance() method for singleton classes, take 2.

base/global_descriptors_posix.cc

Index: base/global_descriptors_posix.cc
diff --git a/base/global_descriptors_posix.cc b/base/global_descriptors_posix.cc
index 8c853a03038bfb39c2cbb14e519a5257a4a11b3f..ecb381ea18a50c9b4acaa736c9b7d9704c83b9e8 100644
--- a/base/global_descriptors_posix.cc
+++ b/base/global_descriptors_posix.cc
@@ -15,6 +15,17 @@ GlobalDescriptors::GlobalDescriptors() {}
 
 GlobalDescriptors::~GlobalDescriptors() {}
 
+// static
+GlobalDescriptors* GlobalDescriptors::GetInstance() {
+  return Singleton<GlobalDescriptors>::get();
+}
+
+// static
+GlobalDescriptors* GlobalDescriptors::GetLeakyInstance() {
+  return Singleton<GlobalDescriptors,
+                   LeakySingletonTraits<GlobalDescriptors> >::get();
+}
+
 int GlobalDescriptors::MaybeGet(Key key) const {
   for (Mapping::const_iterator
        i = descriptors_.begin(); i != descriptors_.end(); ++i) {