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

components/tracing/child_trace_message_filter.cc

Index: components/tracing/child_trace_message_filter.cc
diff --git a/components/tracing/child_trace_message_filter.cc b/components/tracing/child_trace_message_filter.cc
index 62e13aec2c0ed8f4ef3bdc84056f24211a509c23..782ff54685e1bbee7222932a1e6e7b85d32bf1d4 100644
--- a/components/tracing/child_trace_message_filter.cc
+++ b/components/tracing/child_trace_message_filter.cc
@@ -7,7 +7,6 @@
 #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;
@@ -69,7 +68,7 @@ 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
@@ -77,14 +76,16 @@ void ChildTraceMessageFilter::OnBeginTracing(
   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
@@ -93,9 +94,6 @@ void ChildTraceMessageFilter::OnEndTracing() {
   // 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() {