[tracing] Send smaps file desciptor to child process for tracing

components/tracing/child_trace_message_filter.cc

 // Copyright (c) 2012 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 "components/tracing/child_trace_message_filter.h"
 
 #include "base/metrics/statistics_recorder.h"
 #include "base/trace_event/trace_event.h"
 #include "components/tracing/child_memory_dump_manager_delegate_impl.h"
-#include "components/tracing/tracing_messages.h"
 #include "ipc/ipc_channel.h"
 
 using base::trace_event::TraceLog;
 
 namespace tracing {
 
 namespace {
 
 const int kMinTimeBetweenHistogramChangesInSeconds = 10;
 
@@ skipping 41 matching lines @@
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 ChildTraceMessageFilter::~ChildTraceMessageFilter() {}
 
 void ChildTraceMessageFilter::OnBeginTracing(
     const std::string& trace_config_str,
     base::TraceTicks browser_time,
-    uint64 tracing_process_id) {
+    TracingMsg_MemoryTracingInfo memory_tracing_info) {
 #if defined(__native_client__)
   // NaCl and system times are offset by a bit, so subtract some time from
   // the captured timestamps. The value might be off by a bit due to messaging
   // latency.
   base::TimeDelta time_offset = base::TraceTicks::Now() - browser_time;
   TraceLog::GetInstance()->SetTimeOffset(time_offset);
 #endif
-  ChildMemoryDumpManagerDelegateImpl::GetInstance()->set_tracing_process_id(
-      tracing_process_id);
+  ChildMemoryDumpManagerDelegateImpl::GetInstance()->SetMemoryTracingInfo(
+      memory_tracing_info);
   TraceLog::GetInstance()->SetEnabled(
       base::trace_event::TraceConfig(trace_config_str),
       base::trace_event::TraceLog::RECORDING_MODE);
 }
 
 void ChildTraceMessageFilter::OnEndTracing() {
+  ChildMemoryDumpManagerDelegateImpl::GetInstance()->ResetMemoryTracingInfo();
+
   TraceLog::GetInstance()->SetDisabled();
 
   // Flush will generate one or more callbacks to OnTraceDataCollected
   // synchronously or asynchronously. EndTracingAck will be sent in the last
   // OnTraceDataCollected. We are already on the IO thread, so the
   // OnTraceDataCollected calls will not be deferred.
   TraceLog::GetInstance()->Flush(
       base::Bind(&ChildTraceMessageFilter::OnTraceDataCollected, this));
-
-  ChildMemoryDumpManagerDelegateImpl::GetInstance()->set_tracing_process_id(
-      base::trace_event::MemoryDumpManager::kInvalidTracingProcessId);
 }
 
 void ChildTraceMessageFilter::OnCancelTracing() {
   TraceLog::GetInstance()->CancelTracing(
       base::Bind(&ChildTraceMessageFilter::OnTraceDataCollected, this));
 }
 
 void ChildTraceMessageFilter::OnEnableMonitoring(
     const std::string& trace_config_str,
     base::TraceTicks browser_time) {
@@ skipping 196 matching lines @@
   }
 }
 
 void ChildTraceMessageFilter::OnClearUMACallback(
     const std::string& histogram_name) {
   histogram_last_changed_ = base::Time();
   base::StatisticsRecorder::ClearCallback(histogram_name);
 }
 
 }  // namespace tracing