[tracing] Add native allocation tracing mode.

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 53532b231242ff567e07486f680c1819cf6bb092..5939ed26daae56a054c2eaa19a2dd0f9a4e439cb 100644
--- a/base/trace_event/memory_dump_manager.cc
+++ b/base/trace_event/memory_dump_manager.cc
@@ -169,7 +169,30 @@ void MemoryDumpManager::EnableHeapProfilingIfNeeded() {
           switches::kEnableHeapProfiling))
     return;
 
-  AllocationContextTracker::SetCaptureEnabled(true);
+  std::string profiling_mode = CommandLine::ForCurrentProcess()
+      ->GetSwitchValueASCII(switches::kEnableHeapProfiling);
+  if (profiling_mode == "") {
+    AllocationContextTracker::SetCaptureMode(
+        AllocationContextTracker::CaptureMode::PSEUDO_STACK);
+  }
+  else if (profiling_mode == switches::kEnableHeapProfilingModeNative) {
+#if ENABLE_NATIVE_ALLOCATION_TRACES
+    AllocationContextTracker::SetCaptureMode(
+        AllocationContextTracker::CaptureMode::NATIVE_STACK);
+#else
+    CHECK(false) << "'" << profiling_mode << "' mode for "
+                 << switches::kEnableHeapProfiling << " flag is not supported "
+                 << "for this platform / build type.";
+#endif
+  } else {
+    CHECK(false) << "Invalid mode '" << profiling_mode << "' for "
+               << switches::kEnableHeapProfiling << " flag.";
+
+    // If the above didn't crash, use some default

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

uh wat?
If the above didn't crash we have some serious problem in chrome and should stop
shipping it :)
CHECK is used to enforce security properties of chrome, if it doesn't work we
are all screwed ant the heap profiler will be the last thing we should care :)
plz just remove lines 190-193

[Dmitry Skiba, 2016/04/22 06:31:15]

Done.

+    AllocationContextTracker::SetCaptureMode(
+        AllocationContextTracker::CaptureMode::PSEUDO_STACK);
+  }
+
   for (auto mdp : dump_providers_)
     mdp->dump_provider->OnHeapProfilingEnabled(true);
   heap_profiling_enabled_ = true;