[tracing] Add SkResourceCache as suballocation to avoid double counting.

base/memory/discardable_shared_memory.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 BASE_MEMORY_DISCARDABLE_SHARED_MEMORY_H_
 #define BASE_MEMORY_DISCARDABLE_SHARED_MEMORY_H_
 
 #include "base/base_export.h"
 #include "base/logging.h"
 #include "base/memory/shared_memory.h"
@@ skipping 11 matching lines @@
 #endif
 
 namespace base {
 
 // Platform abstraction for discardable shared memory.
 //
 // This class is not thread-safe. Clients are responsible for synchronizing
 // access to an instance of this class.
 class BASE_EXPORT DiscardableSharedMemory {
  public:
+  // Used by other allocators to expess sub-allocation from discardable memory
+  // heap for tracing. To expess any suballocation, the dump providers need to
+  // create a sub-allocation edge from this node.
+  // Eg. : ProcessMemoryDump::AddSuballocation(skia_dump_guid,

[petrcermak, 2015/07/29 16:38:59]

nit: There should be a dot after "E" and no space before the colon.

[ssid, 2015/07/29 16:57:37]

Done.

+  //                                           kDiscardableSegmentsDumpName);

[petrcermak, 2015/07/29 16:38:59]

How is this related to the constant??? Shouldn't it be
s/kDiscardableSegmentsDumpName/kAllocatedObjectsDumpName/?

[ssid, 2015/07/29 16:57:37]

Done.

+  static const char kAllocatedObjectsDumpName[];
+
   enum LockResult { SUCCESS, PURGED, FAILED };
 
   DiscardableSharedMemory();
 
   // Create a new DiscardableSharedMemory object from an existing, open shared
   // memory file. Memory must be locked.
   explicit DiscardableSharedMemory(SharedMemoryHandle handle);
 
   // Closes any open files.
   virtual ~DiscardableSharedMemory();
@@ skipping 99 matching lines @@
   // synchronized somehow. Use a collision warner to detect incorrect usage.
   DFAKE_MUTEX(thread_collision_warner_);
   Time last_known_usage_;
 
   DISALLOW_COPY_AND_ASSIGN(DiscardableSharedMemory);
 };
 
 }  // namespace base
 
 #endif  // BASE_MEMORY_DISCARDABLE_SHARED_MEMORY_H_