Adding shutdown tracing capabilities

content/public/common/content_switches.cc

 // Copyright (c) 2012 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 "content/public/common/content_switches.h"
 
 namespace switches {
 
 // By default, file:// URIs cannot read other file:// URIs. This is an
 // override for developers who need the old behavior for testing.
@@ skipping 775 matching lines @@
 // sending them to the renderer.
 const char kTapDownDeferralTimeMs[]         = "tap-down-deferral-time";
 
 // Allows for forcing socket connections to http/https to use fixed ports.
 const char kTestingFixedHttpPort[]          = "testing-fixed-http-port";
 const char kTestingFixedHttpsPort[]         = "testing-fixed-https-port";
 
 // Runs the security test for the renderer sandbox.
 const char kTestSandbox[]                   = "test-sandbox";
 
+// Causes TRACE_EVENT flags to be recorded beginning with shutdown. Optionally,
+// can specify the specific trace categories to include (e.g.
+// --trace-shutdown=base,net) otherwise, all events are recorded. Setting this
+// flag results in the first call to BeginTracing() to receive all trace events

[James Cook, 2013/08/30 22:54:02]

Is the part of the comment about BeginTracing() accurate?

[Mr4D (OOO till 08-26), 2013/08/31 02:03:44]

Done.

+// since startup. In Chrome, you may find --trace-shutdown-file to control the
+// auto-saving of the trace (not supported in the base-only TraceLog component).
+const char kTraceShutdown[]                 = "trace-shutdown";
+
+// If supplied, sets the file which shutdown tracing will be stored into, if
+// omitted the default will be used "chrometrace.log" in the current directory.

[James Cook, 2013/08/30 22:54:02]

Update this to match the other filename if you change it

[Mr4D (OOO till 08-26), 2013/08/31 02:03:44]

Somehow .json for logfiles makes no sense. ".json" is a javascript exchange
format which makes every programmer think that it must have something to do with
with some Javascript program - bit surely not with a log file. Since the startup
default name is also .log - this should also remain this way.

+// Has no effect unless --trace-shutdown is also supplied.
+// Example: --trace-shutdown --trace-shutdown-file=/tmp/trace_event.log
+const char kTraceShutdownFile[]             = "trace-shutdown-file";
+
 // Causes TRACE_EVENT flags to be recorded from startup. Optionally, can
 // specify the specific trace categories to include (e.g.
 // --trace-startup=base,net) otherwise, all events are recorded. Setting this
 // flag results in the first call to BeginTracing() to receive all trace events
 // since startup. In Chrome, you may find --trace-startup-file and
 // --trace-startup-duration to control the auto-saving of the trace (not
 // supported in the base-only TraceLog component).
 const char kTraceStartup[]                  = "trace-startup";
 
 // Sets the time in seconds until startup tracing ends. If omitted a default of
@@ skipping 137 matching lines @@
 #endif
 
 #if defined(USE_AURA)
 // Forces usage of the test compositor. Needed to run ui tests on bots.
 extern const char kTestCompositor[]         = "test-compositor";
 #endif
 
 // Don't dump stuff here, follow the same order as the header.
 
 }  // namespace switches