Cleaner fall-back stack capture for --enable-heap-profiling=native.

base/trace_event/memory_dump_manager.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/trace_event/memory_dump_manager.h"
 
 #include <inttypes.h>
 #include <stdio.h>
 
 #include <algorithm>
@@ skipping 177 matching lines @@
   if (!CommandLine::InitializedForCurrentProcess() ||
       !CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableHeapProfiling))
     return;
 
   std::string profiling_mode = CommandLine::ForCurrentProcess()
       ->GetSwitchValueASCII(switches::kEnableHeapProfiling);
   if (profiling_mode == "") {
     AllocationContextTracker::SetCaptureMode(
         AllocationContextTracker::CaptureMode::PSEUDO_STACK);
-#if (BUILDFLAG(CAN_UNWIND_WITH_FRAME_POINTERS) || !defined(NDEBUG))
+#if !defined(OS_NACL)
   } else if (profiling_mode == switches::kEnableHeapProfilingModeNative) {
-    // We need frame pointers for native tracing to work, and they are
-    // enabled in profiling and debug builds.
+    // If we don't have frame pointers then native tracing falls-back to
+    // using base::debug::StackTrace, which may be slow.
     AllocationContextTracker::SetCaptureMode(
         AllocationContextTracker::CaptureMode::NATIVE_STACK);
-#endif
+#endif  // !defined(OS_NACL)
 #if BUILDFLAG(ENABLE_MEMORY_TASK_PROFILER)
   } else if (profiling_mode == switches::kEnableHeapProfilingTaskProfiler) {
     // Enable heap tracking, which in turn enables capture of heap usage
     // tracking in tracked_objects.cc.
     if (!base::debug::ThreadHeapUsageTracker::IsHeapTrackingEnabled())
       base::debug::ThreadHeapUsageTracker::EnableHeapTracking();
-#endif
+#endif  // BUILDFLAG(ENABLE_MEMORY_TASK_PROFILER)
   } else {
     CHECK(false) << "Invalid mode '" << profiling_mode << "' for "
                << switches::kEnableHeapProfiling << " flag.";
   }
 
   for (auto mdp : dump_providers_)
     mdp->dump_provider->OnHeapProfilingEnabled(true);
   heap_profiling_enabled_ = true;
 }
 
@@ skipping 759 matching lines @@
   if (iter == process_dumps.end()) {
     std::unique_ptr<ProcessMemoryDump> new_pmd(
         new ProcessMemoryDump(session_state, dump_args));
     iter = process_dumps.insert(std::make_pair(pid, std::move(new_pmd))).first;
   }
   return iter->second.get();
 }
 
 }  // namespace trace_event
 }  // namespace base