Bug 1401662 - don't inline nsThreadManager::get(); r=erahm

Defining get() in the declaration of nsThreadManager implicitly sticks
an "inline" on the function, which is not what we want: inlining it
spreads around a lot of static initialization code.  Providing an
out-of-line definition is much better in terms of code size.

xpcom/threads/nsThreadManager.cpp

@@ -105,6 +105,13 @@ NS_IMPL_CI_INTERFACE_GETTER(nsThreadManager, nsIThreadManager)
 
 //-----------------------------------------------------------------------------
 
+/*static*/ nsThreadManager&
+nsThreadManager::get()
+{
+  static nsThreadManager sInstance;
+  return sInstance;
+}
+
 nsresult
 nsThreadManager::Init()
 {

xpcom/threads/nsThreadManager.h

@@ -20,11 +20,7 @@ public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSITHREADMANAGER
 
-  static nsThreadManager& get()
-  {
-    static nsThreadManager sInstance;
-    return sInstance;
-  }
+  static nsThreadManager& get();
 
   nsresult Init();