Refactor read and write buffers.

src/images/SkImageRef_GlobalPool.cpp

Index: src/images/SkImageRef_GlobalPool.cpp
diff --git a/src/images/SkImageRef_GlobalPool.cpp b/src/images/SkImageRef_GlobalPool.cpp
index f91cebabbf8e7e0c26f06533e35122bc12b62039..2659e8b4711ec877bbffb421426f61ce36588266 100644
--- a/src/images/SkImageRef_GlobalPool.cpp
+++ b/src/images/SkImageRef_GlobalPool.cpp
@@ -64,7 +64,7 @@ void SkImageRef_GlobalPool::onUnlockPixels() {
     GetGlobalPool()->canLosePixels(this);
 }
 
-SkImageRef_GlobalPool::SkImageRef_GlobalPool(SkFlattenableReadBuffer& buffer)
+SkImageRef_GlobalPool::SkImageRef_GlobalPool(SkReadBuffer& buffer)
         : INHERITED(buffer, &gGlobalPoolMutex) {
     SkASSERT(&gGlobalPoolMutex == this->mutex());
     SkAutoMutexAcquire ac(gGlobalPoolMutex);