Fix the size dumped by child discardable manager for tracing.

content/common/discardable_shared_memory_heap.h

 // Copyright 2014 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 CONTENT_COMMON_DISCARDABLE_SHARED_MEMORY_HEAP_H_
 #define CONTENT_COMMON_DISCARDABLE_SHARED_MEMORY_HEAP_H_
 
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/containers/linked_list.h"
@@ skipping 100 matching lines @@
                         const base::Closure& deleted_callback);
     ~ScopedMemorySegment();
 
     bool IsUsed() const;
     bool IsResident() const;
 
     bool ContainsSpan(Span* span) const;
 
     base::trace_event::MemoryAllocatorDump* CreateMemoryAllocatorDump(
         Span* span,
+        size_t block_size,

[reveman, 2015/08/26 16:04:59]

Maybe remove |span| and |block_size| args and just pass "size_t size" here?
we're not using |span| for anything but a DCHECK..

         const char* name,
         base::trace_event::ProcessMemoryDump* pmd) const;
 
     // Used for dumping memory statistics from the segment to chrome://tracing.
     void OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd) const;
 
    private:
     DiscardableSharedMemoryHeap* const heap_;
     scoped_ptr<base::DiscardableSharedMemory> shared_memory_;
     const size_t size_;
@@ skipping 36 matching lines @@
   // is a free list of runs that consist of k blocks. The 256th entry is a
   // free list of runs that have length >= 256 blocks.
   base::LinkedList<Span> free_spans_[256];
 
   DISALLOW_COPY_AND_ASSIGN(DiscardableSharedMemoryHeap);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_DISCARDABLE_SHARED_MEMORY_HEAP_H_