[tracing] Add native allocation tracing mode.

base/base_switches.cc

Index: base/base_switches.cc
diff --git a/base/base_switches.cc b/base/base_switches.cc
index d1a38e4b21e4c2b44a4897f98cf4f59d2bc2567d..fa0bc3337189bc9986b8a655d93342ecfa127edb 100644
--- a/base/base_switches.cc
+++ b/base/base_switches.cc
@@ -20,6 +20,10 @@ const char kEnableCrashReporter[]           = "enable-crash-reporter";
 // the memory-infra category is enabled.
 const char kEnableHeapProfiling[]           = "enable-heap-profiling";
 
+// Report native (walk the stack) allocation traces. By default pseudo stacks
+// derived from trace events are reported.
+const char kEnableHeapProfilingModeNative[] = "native";

[Primiano Tucci (use gerrit), 2016/04/21 20:08:21]

THougt for next CL: mariakhomenko@ is adding some heap-profiler config in the
traceconfig. Maybe this native vs pseudo switch should also be there.
Fine for now to not block this CL, but maybe we should think to that option
really soon.

+
 // Generates full memory crash dump.
 const char kFullMemoryCrashReport[]         = "full-memory-crash-report";