[tracing] Dump child processes' memory metrics in browser

base/trace_event/process_memory_maps_dump_provider.cc

Index: base/trace_event/process_memory_maps_dump_provider.cc
diff --git a/base/trace_event/process_memory_maps_dump_provider.cc b/base/trace_event/process_memory_maps_dump_provider.cc
index 19f8d891618c10be3ae1d7a65d088b7aecacfb42..3059d392ad0ff20e2a381189388ca443b10e6690 100644
--- a/base/trace_event/process_memory_maps_dump_provider.cc
+++ b/base/trace_event/process_memory_maps_dump_provider.cc
@@ -136,13 +136,14 @@ uint32 ReadLinuxProcSmapsFile(FILE* smaps_file, ProcessMemoryMaps* pmm) {
 }  // namespace
 
 // static
-ProcessMemoryMapsDumpProvider* ProcessMemoryMapsDumpProvider::GetInstance() {
-  return Singleton<ProcessMemoryMapsDumpProvider,
-                   LeakySingletonTraits<ProcessMemoryMapsDumpProvider>>::get();
+scoped_ptr<ProcessMemoryMapsDumpProvider>
+ProcessMemoryMapsDumpProvider::CreateForProcess(ProcessHandle process) {
+  return make_scoped_ptr(new ProcessMemoryMapsDumpProvider(process));
 }
 
-ProcessMemoryMapsDumpProvider::ProcessMemoryMapsDumpProvider() {
-}
+ProcessMemoryMapsDumpProvider::ProcessMemoryMapsDumpProvider(
+    ProcessHandle process)
+    : process_(process) {}
 
 ProcessMemoryMapsDumpProvider::~ProcessMemoryMapsDumpProvider() {
 }