Order function definitions in base/ according to the header.

base/at_exit.cc

Index: base/at_exit.cc
diff --git a/base/at_exit.cc b/base/at_exit.cc
index 9fdfd77d9e8998582004d8aa009026b972cbaed6..e6618a02db86a34e41611dd0c8e513dea0826870 100644
--- a/base/at_exit.cc
+++ b/base/at_exit.cc
@@ -18,11 +18,6 @@ AtExitManager::AtExitManager() : next_manager_(NULL) {
   g_top_manager = this;
 }
 
-AtExitManager::AtExitManager(bool shadow) : next_manager_(g_top_manager) {
-  DCHECK(shadow || !g_top_manager);
-  g_top_manager = this;
-}
-
 AtExitManager::~AtExitManager() {
   if (!g_top_manager) {
     NOTREACHED() << "Tried to ~AtExitManager without an AtExitManager";
@@ -64,4 +59,9 @@ void AtExitManager::ProcessCallbacksNow() {
   }
 }
 
+AtExitManager::AtExitManager(bool shadow) : next_manager_(g_top_manager) {
+  DCHECK(shadow || !g_top_manager);
+  g_top_manager = this;
+}
+
 }  // namespace base