Make classes and structures in core/loader fast-allocated.

Source/core/loader/EmptyClients.h

Index: Source/core/loader/EmptyClients.h
diff --git a/Source/core/loader/EmptyClients.h b/Source/core/loader/EmptyClients.h
index adcf55e33ac3923b152a03f21ac56b972b3b96e0..30073677579348b2286ec1c96f8d8816113b6403 100644
--- a/Source/core/loader/EmptyClients.h
+++ b/Source/core/loader/EmptyClients.h
@@ -263,6 +263,7 @@ protected:
 };
 
 class CORE_EXPORT EmptyTextCheckerClient : public TextCheckerClient {
+    DISALLOW_ALLOCATION();

[haraken, 2015/08/27 05:44:48]

Don't we want to add this to the parent class?

[tasak, 2015/08/27 07:50:48]

Looking at only EmptyTextCheckerClient, it sounds ok. However, looking at
another subclass of TextCheckerClient, i.e. SpellCheckerClientImpl:

  class  SpellCheckerClientImpl final : public SpellCheckerClient, public
TextCheckerClient { ... }

SpellCheckerClientImpl is a subclass of both SpellCheckerClient and
TextCheckerClient.
TextCheckerClient and SpellCheckerClient work in the almost the same way (i.e.
(just defining interfaces).

I'm not sure which class should be DISALLOW_ALLOCATION.
We need DISALLOW_ALLOCATION_MIXIN?

 public:
     ~EmptyTextCheckerClient() { }