[tracing] Fix V8 and PartitionAlloc dump provider for background mode

gin/v8_isolate_memory_dump_provider.cc

Index: gin/v8_isolate_memory_dump_provider.cc
diff --git a/gin/v8_isolate_memory_dump_provider.cc b/gin/v8_isolate_memory_dump_provider.cc
index 8c3ad6a9c0acbff03f85e34cb34db2c5b51f998a..1e0e762dbbe0c71d324763cd7d553075292020cb 100644
--- a/gin/v8_isolate_memory_dump_provider.cc
+++ b/gin/v8_isolate_memory_dump_provider.cc
@@ -131,9 +131,11 @@ void V8IsolateMemoryDumpProvider::DumpHeapStatistics(
                                           system_allocator_name);
   }
 
-  // If light dump is requested, then object statistics are not dumped
-  if (args.level_of_detail == base::trace_event::MemoryDumpLevelOfDetail::LIGHT)
+  // Only if heavy dump is requested, then object statistics are dumped.

[Primiano Tucci (use gerrit), 2016/06/01 09:58:26]

The wording of this comment is a bit odd now.
Maybe:
// Dump object statistics only for detailed dumps.

[ssid, 2016/06/01 18:53:46]

Done.

+  if (args.level_of_detail !=
+      base::trace_event::MemoryDumpLevelOfDetail::DETAILED) {
     return;
+  }
 
   // Dump statistics of the heap's live objects from last GC.
   // TODO(primiano): these should not be tracked in the same trace event as they