[tracing] Dump child processes' memory metrics in browser

components/tracing/child_memory_dump_manager_delegate_impl.cc

 // Copyright 2015 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_memory_dump_manager_delegate_impl.h"
 
 #include "base/single_thread_task_runner.h"

[Primiano Tucci (use gerrit), 2015/11/17 10:44:12]

include what you use: add explicit build_config.h include

[ssid, 2015/11/17 13:55:06]

Done.

 #include "components/tracing/child_trace_message_filter.h"
+#include "components/tracing/process_metrics_memory_dump_manager.h"
 
 namespace tracing {
 
 namespace {
 void AbortDumpRequest(const base::trace_event::MemoryDumpRequestArgs& args,
                       const base::trace_event::MemoryDumpCallback& callback) {
   if (!callback.is_null())
     callback.Run(args.dump_guid, false /* success */);
 }
 }  // namespace
@@ skipping 23 matching lines @@
   ctmf_ = ctmf;
 
   {
     base::AutoLock lock(lock_);
     ctmf_task_runner_ = task_runner;
   }
 
   if (ctmf) {
     base::trace_event::MemoryDumpManager::GetInstance()->Initialize(
       this /* delegate */, false /* is_coordinator */);
+
+#if !defined(OS_LINUX)
+    // Do not register in linux due to sandbox.

[Primiano Tucci (use gerrit), 2015/11/17 10:44:12]

Make this more explicit and say: on Linux the browser process takes care of
dumping process stats of child processes. The child themselves are not allowed
to do so due to the BPF sandbox.

[ssid, 2015/11/17 13:55:06]

Done.

+    tracing::ProcessMetricsMemoryDumpManager::GetInstance()->RegisterForProcess(
+        base::kNullProcessHandle);
+#endif
   }
 }
 
 // Invoked in child processes by the MemoryDumpManager.
 void ChildMemoryDumpManagerDelegateImpl::RequestGlobalMemoryDump(
     const base::trace_event::MemoryDumpRequestArgs& args,
     const base::trace_event::MemoryDumpCallback& callback) {
   // RequestGlobalMemoryDump can be called on any thread, cannot access
   // ctmf_task_runner_ as it could be racy.
   scoped_refptr<base::SingleThreadTaskRunner> ctmf_task_runner;
@@ skipping 26 matching lines @@
 
   // Send the request up to the browser process' MessageDumpmanager.
   ctmf_->SendGlobalMemoryDumpRequest(args, callback);
 }
 
 uint64 ChildMemoryDumpManagerDelegateImpl::GetTracingProcessId() const {
   return tracing_process_id_;
 }
 
 }  // namespace tracing