[tracing] Introduce MemoryDumpArgs to enable light and heavy dumps

content/common/host_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/common/host_discardable_shared_memory_manager.h"
 
 #include <algorithm>
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
@@ skipping 136 matching lines @@
   // Close file descriptor to avoid running out.
   memory->Close();
   return make_scoped_ptr(new DiscardableMemoryImpl(
       memory.Pass(),
       base::Bind(
           &HostDiscardableSharedMemoryManager::DeletedDiscardableSharedMemory,
           base::Unretained(this), new_id, ChildProcessHost::kInvalidUniqueID)));
 }
 
 bool HostDiscardableSharedMemoryManager::OnMemoryDump(
+    const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {
   base::AutoLock lock(lock_);
   for (const auto& process_entry : processes_) {
     const int child_process_id = process_entry.first;
     const MemorySegmentMap& process_segments = process_entry.second;
     for (const auto& segment_entry : process_segments) {
       const int segment_id = segment_entry.first;
       const MemorySegment* segment = segment_entry.second.get();
       std::string dump_name = base::StringPrintf(
           "discardable/process_%x/segment_%d", child_process_id, segment_id);
@@ skipping 288 matching lines @@
 
   enforce_memory_policy_pending_ = true;
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE,
       base::Bind(&HostDiscardableSharedMemoryManager::EnforceMemoryPolicy,
                  weak_ptr_factory_.GetWeakPtr()),
       base::TimeDelta::FromMilliseconds(kEnforceMemoryPolicyDelayMs));
 }
 
 }  // namespace content