Stack sampling profiler: re-enable stack collection for stacks terminated by leaf functions

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 0c7098c582528da5ee10c1685c92db4fc61ba0c3..9632734e6df826f2377f2c564335e4778c84df2e 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -540,6 +540,16 @@ void LaunchDevToolsHandlerIfNeeded(const base::CommandLine& command_line) {
   }
 }
 
+base::StackSamplingProfiler::SamplingParams GetStartupSamplingParams() {
+  // Sample at 10Hz for 30 seconds.
+  base::StackSamplingProfiler::SamplingParams params;
+  params.initial_delay = base::TimeDelta::FromMilliseconds(0);
+  params.bursts = 1;
+  params.samples_per_burst = 300;
+  params.sampling_interval = base::TimeDelta::FromMilliseconds(100);
+  return params;
+}
+
 }  // namespace
 
 namespace chrome_browser {
@@ -568,11 +578,26 @@ ChromeBrowserMainParts::ChromeBrowserMainParts(
       startup_watcher_(new StartupTimeBomb()),
       shutdown_watcher_(new ShutdownWatcherHelper()),
       browser_field_trials_(parameters.command_line),
+      sampling_profiler_(
+          base::PlatformThread::CurrentId(),
+          GetStartupSamplingParams(),
+          metrics::CallStackProfileMetricsProvider::GetProfilerCallback(
+              metrics::CallStackProfileMetricsProvider::Params(
+                  metrics::CallStackProfileMetricsProvider::PROCESS_STARTUP,
+                  false))),
       profile_(NULL),
       run_message_loop_(true),
       notify_result_(ProcessSingleton::PROCESS_NONE),
       local_state_(NULL),
       restart_last_session_(false) {
+  const version_info::Channel channel =
+      chrome::VersionInfo::GetChannel();
+  if (channel == version_info::Channel::UNKNOWN ||
+      channel == version_info::Channel::CANARY ||
+      channel == version_info::Channel::DEV) {
+    sampling_profiler_.Start();
+  }
+
   // If we're running tests (ui_task is non-null).
   if (parameters.ui_task)
     browser_defaults::enable_help_app = false;