Update from https://crrev.com/317530

base/trace_event/memory_dump_manager.cc

Index: base/trace_event/memory_dump_manager.cc
diff --git a/base/trace_event/memory_dump_manager.cc b/base/trace_event/memory_dump_manager.cc
index bf631b34bea033cba4c95f76d4f73439ed703d3f..c8be8f89312a34d5b0bdd3996c3abebbc143f10b 100644
--- a/base/trace_event/memory_dump_manager.cc
+++ b/base/trace_event/memory_dump_manager.cc
@@ -9,22 +9,15 @@
 #include "base/compiler_specific.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "base/trace_event/process_memory_dump.h"
-
-// TODO(primiano): in a separate CL rename DeleteTraceLogForTesting into
-// something like base::internal::TeardownSingletonForTesting so we don't have
-// to add a new friend to singleton each time.
-class DeleteTraceLogForTesting {
- public:
-  static void Delete() {
-    Singleton<
-        base::trace_event::MemoryDumpManager,
-        LeakySingletonTraits<base::trace_event::MemoryDumpManager>>::OnExit(0);
-  }
-};
+#include "base/trace_event/trace_event_argument.h"
 
 namespace base {
 namespace trace_event {
 
+namespace {
+MemoryDumpManager* g_instance_for_testing = nullptr;
+}
+
 // TODO(primiano): this should be smarter and should do something similar to
 // trace event synthetic delays.
 const char MemoryDumpManager::kTraceCategory[] =
@@ -32,13 +25,16 @@ const char MemoryDumpManager::kTraceCategory[] =
 
 // static
 MemoryDumpManager* MemoryDumpManager::GetInstance() {
+  if (g_instance_for_testing)
+    return g_instance_for_testing;
+
   return Singleton<MemoryDumpManager,
                    LeakySingletonTraits<MemoryDumpManager>>::get();
 }
 
 // static
-void MemoryDumpManager::DeleteForTesting() {
-  DeleteTraceLogForTesting::Delete();
+void MemoryDumpManager::SetInstanceForTesting(MemoryDumpManager* instance) {
+  g_instance_for_testing = instance;
 }
 
 MemoryDumpManager::MemoryDumpManager() : memory_tracing_enabled_(0) {
@@ -96,15 +92,14 @@ void MemoryDumpManager::BroadcastDumpRequest() {
 // Creates a dump point for the current process and appends it to the trace.
 void MemoryDumpManager::CreateLocalDumpPoint() {
   AutoLock lock(lock_);
-  // TRACE_EVENT_* macros don't induce scoped_refptr type inference, hence we
-  // need the base ConvertableToTraceFormat and the upcast below. The
-  // alternative would be unnecessarily expensive (double Acquire/Release).
-  scoped_refptr<ConvertableToTraceFormat> pmd(new ProcessMemoryDump());
+  scoped_ptr<ProcessMemoryDump> pmd(new ProcessMemoryDump());
 
   for (MemoryDumpProvider* dump_provider : dump_providers_enabled_) {
-    dump_provider->DumpInto(static_cast<ProcessMemoryDump*>(pmd.get()));
+    dump_provider->DumpInto(pmd.get());
   }
 
+  scoped_refptr<TracedValue> value(new TracedValue());
+  pmd->AsValueInto(value.get());
   // TODO(primiano): add the dump point to the trace at this point.
 }