[tracing] Display the resident size of the discardable memory segments

content/common/host_discardable_shared_memory_manager.cc

Index: content/common/host_discardable_shared_memory_manager.cc
diff --git a/content/common/host_discardable_shared_memory_manager.cc b/content/common/host_discardable_shared_memory_manager.cc
index 8af1d4dcc09912c2a6569fec88df88a33e54a0d7..413776be9233a22d53136a0d7fc676928be749df 100644
--- a/content/common/host_discardable_shared_memory_manager.cc
+++ b/content/common/host_discardable_shared_memory_manager.cc
@@ -185,6 +185,20 @@ bool HostDiscardableSharedMemoryManager::OnMemoryDump(
                       base::trace_event::MemoryAllocatorDump::kUnitsBytes,
                       segment->memory()->mapped_size());
 
+#if defined(COUNT_RESIDENT_BYTES_SUPPORTED)
+      if (args.level_of_detail ==
+          base::trace_event::MemoryDumpLevelOfDetail::DETAILED) {
+        int64 resident_size =

[reveman, 2015/10/07 13:41:44]

nit: size_t as that's now the return type for CountResidentBytes

[ssid, 2015/10/07 14:46:45]

Done.

+            base::trace_event::ProcessMemoryDump::CountResidentBytes(
+                segment->memory()->memory(), segment->memory()->mapped_size());
+        if (resident_size >= 0) {

[reveman, 2015/10/07 13:41:44]

nit: s/resident_size >= 0/resident_size/ after switching to size_t above

[ssid, 2015/10/07 14:46:45]

0 is still reported. removing if.

+          dump->AddScalar("resident_size",
+                          base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                          static_cast<uint64>(resident_size));
+        }
+      }
+#endif  // defined(COUNT_RESIDENT_BYTES_SUPPORTED)
+
       // Host can only tell if whole segment is locked or not.
       dump->AddScalar(
           "locked_size", base::trace_event::MemoryAllocatorDump::kUnitsBytes,