base: Rename discardable memory allocator interface and remove unnecessary class.

content/child/child_discardable_shared_memory_manager.h

Index: content/child/child_discardable_shared_memory_manager.h
diff --git a/content/child/child_discardable_shared_memory_manager.h b/content/child/child_discardable_shared_memory_manager.h
index 27c8b83c9feea3074b5ee07652007b2c43c2b3df..97affdf02da8072bf619660302128a39ee933987 100644
--- a/content/child/child_discardable_shared_memory_manager.h
+++ b/content/child/child_discardable_shared_memory_manager.h
@@ -5,7 +5,7 @@
 #ifndef CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_
 #define CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_
 
-#include "base/memory/discardable_memory_shmem_allocator.h"
+#include "base/memory/discardable_memory_allocator.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "content/child/thread_safe_sender.h"
@@ -14,16 +14,16 @@
 
 namespace content {
 
-// Implementation of DiscardableMemoryShmemAllocator that allocates
+// Implementation of DiscardableMemoryAllocator that allocates
 // discardable memory segments through the browser process.
 class CONTENT_EXPORT ChildDiscardableSharedMemoryManager
-    : public base::DiscardableMemoryShmemAllocator {
+    : public base::DiscardableMemoryAllocator {
  public:
   explicit ChildDiscardableSharedMemoryManager(ThreadSafeSender* sender);
   ~ChildDiscardableSharedMemoryManager() override;
 
-  // Overridden from base::DiscardableMemoryShmemAllocator:
-  scoped_ptr<base::DiscardableMemoryShmemChunk> AllocateLockedDiscardableMemory(
+  // Overridden from base::DiscardableMemoryAllocator:
+  scoped_ptr<base::DiscardableMemory> AllocateLockedDiscardableMemory(
       size_t size) override;
 
   // Release memory and associated resources that have been purged.