Implement profiler log writing at shutdown

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index b1bea82094ce144239215003e53032a1b274b9bf..370e06ad46e7fb0e058a0ca0593a59a30d4acc33 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -937,6 +937,10 @@ const char kProfilingAtStart[]              = "profiling-at-start";
 // The default is chrome-profile-{pid}.
 const char kProfilingFile[]                 = "profiling-file";
 
+// Specifies a path for the output of task-level profiling which can be loaded
+// and viewed in about:profiler.
+const char kProfilingOutputFile[]            = "profiling-output-file";
+
 // Controls whether profile data is periodically flushed to a file. Normally
 // the data gets written on exit but cases exist where chrome doesn't exit
 // cleanly (especially when using single-process). A time in seconds can be