[tracing] Introduce MemoryDumpArgs to enable light and heavy dumps

content/child/child_discardable_shared_memory_manager.cc

 // 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.
 
 #include "content/child/child_discardable_shared_memory_manager.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
 #include "base/debug/crash_logging.h"
 #include "base/memory/discardable_memory.h"
@@ skipping 173 matching lines @@
         leftover->length() * base::GetPageSize());
     heap_.MergeIntoFreeLists(leftover.Pass());
   }
 
   MemoryUsageChanged(heap_.GetSize(), heap_.GetSizeOfFreeLists());
 
   return make_scoped_ptr(new DiscardableMemoryImpl(this, new_span.Pass()));
 }
 
 bool ChildDiscardableSharedMemoryManager::OnMemoryDump(
+    const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {
   base::AutoLock lock(lock_);
   return heap_.OnMemoryDump(pmd);
 }
 
 void ChildDiscardableSharedMemoryManager::ReleaseFreeMemory() {
   base::AutoLock lock(lock_);
 
   size_t heap_size_prior_to_releasing_memory = heap_.GetSize();
 
@@ skipping 86 matching lines @@
       "discardable-memory-allocated";
   base::debug::SetCrashKeyValue(kDiscardableMemoryAllocatedKey,
                                 base::Uint64ToString(new_bytes_total));
 
   static const char kDiscardableMemoryFreeKey[] = "discardable-memory-free";
   base::debug::SetCrashKeyValue(kDiscardableMemoryFreeKey,
                                 base::Uint64ToString(new_bytes_free));
 }
 
 }  // namespace content