Make SkMemory.h and adjust all files for usage.

This will be rolled out in three stages:
1) make SkMemory.h and have SkTypes.h include it.
2) Adjust chromium and android.
3) no long include SkMemory.h in SkTypes.h

Change-Id: If360ef5e1164d88f50b03f279e2e963ca2f57d5d
Reviewed-on: https://skia-review.googlesource.com/9874
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Herb Derby <herb@google.com>
diff --git a/src/lazy/SkDiscardableMemoryPool.cpp b/src/lazy/SkDiscardableMemoryPool.cpp
index 6ced5bf..fece7f0 100644
--- a/src/lazy/SkDiscardableMemoryPool.cpp
+++ b/src/lazy/SkDiscardableMemoryPool.cpp
@@ -8,6 +8,7 @@
 #include "SkDiscardableMemory.h"
 #include "SkDiscardableMemoryPool.h"
 #include "SkImageGenerator.h"
+#include "SkMemory.h"
 #include "SkMutex.h"
 #include "SkOnce.h"
 #include "SkTInternalLList.h"