[tracing] Add a dump provider to dump process memory totals.

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..ca824eb16245a6256a34d9bcb289338047918ab9 100644
--- a/base/trace_event/memory_dump_manager.cc
+++ b/base/trace_event/memory_dump_manager.cc
@@ -9,6 +9,7 @@
 #include "base/compiler_specific.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "base/trace_event/process_memory_dump.h"
+#include "base/trace_event/trace_event_argument.h"
 
 // TODO(primiano): in a separate CL rename DeleteTraceLogForTesting into
 // something like base::internal::TeardownSingletonForTesting so we don't have
@@ -96,15 +97,14 @@ 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.
 }