[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..27c67652550b48a31dd6a49f2afb0d069761cec6 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
@@ -99,12 +100,14 @@ void MemoryDumpManager::CreateLocalDumpPoint() {
   // 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());

[Sami, 2015/02/19 12:07:05]

Is this cast trickery now obsolete?

[Primiano Tucci (use gerrit), 2015/02/19 12:18:12]

Oh right (FTR: skyostil@ was referring to line 106 below)

[Sami, 2015/02/19 16:16:36]

Right, and also to the comment above this line :) I guess you can update it
while adding the code to actually save the dump into the trace.

 
   for (MemoryDumpProvider* dump_provider : dump_providers_enabled_) {
     dump_provider->DumpInto(static_cast<ProcessMemoryDump*>(pmd.get()));
   }
 
+  scoped_refptr<TracedValue> value(new TracedValue());
+  pmd->AsValueInto(value.get());
   // TODO(primiano): add the dump point to the trace at this point.
 }