Align ashmem region sizes to page size after ashmem creation failed.

base/memory/discardable_memory_allocator_android.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_MEMORY_DISCARDABLE_MEMORY_ALLOCATOR_H_
 #define BASE_MEMORY_DISCARDABLE_MEMORY_ALLOCATOR_H_
 
 #include <string>
 
 #include "base/base_export.h"
@@ skipping 26 matching lines @@
   // ashmem regions and is expected to be greater or equal than 32 MBytes.
   DiscardableMemoryAllocator(const std::string& name,
                              size_t ashmem_region_size);
 
   ~DiscardableMemoryAllocator();
 
   // Note that the allocator must outlive the returned DiscardableMemory
   // instance.
   scoped_ptr<DiscardableMemory> Allocate(size_t size);
 
+  // Returns the size of the last ashmem region which was created. This is used
+  // for testing only.
+  size_t last_ashmem_region_size() const;
+
  private:
   class AshmemRegion;
   class DiscardableAshmemChunk;
 
   void DeleteAshmemRegion_Locked(AshmemRegion* region);
 
-  base::ThreadChecker thread_checker_;
+  ThreadChecker thread_checker_;
   const std::string name_;
   const size_t ashmem_region_size_;
-  base::Lock lock_;
+  mutable Lock lock_;
+  size_t last_ashmem_region_size_;
   ScopedVector<AshmemRegion> ashmem_regions_;
 
   DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryAllocator);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_MEMORY_DISCARDABLE_MEMORY_ALLOCATOR_H_