Revert of [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 fa0bc3337189bc9986b8a655d93342ecfa127edb..d1a38e4b21e4c2b44a4897f98cf4f59d2bc2567d 100644
--- a/base/base_switches.cc
+++ b/base/base_switches.cc
@@ -19,10 +19,6 @@
 // detailed breakdown of memory usage can be presented in chrome://tracing when
 // 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";
 
 // Generates full memory crash dump.
 const char kFullMemoryCrashReport[]         = "full-memory-crash-report";