[Startup Tracing] Enable startup tracing from config file

mojo/common/BUILD.gn

Index: mojo/common/BUILD.gn
diff --git a/mojo/common/BUILD.gn b/mojo/common/BUILD.gn
index e87167c6cd30955f5103f983876dff6b4f99c710..f5f08c8ac106708caa2fe656199a8c55e17b4be7 100644
--- a/mojo/common/BUILD.gn
+++ b/mojo/common/BUILD.gn
@@ -39,6 +39,7 @@ component("common_base") {
   deps = [
     "//base",
     "//base/third_party/dynamic_annotations",
+    "//components/tracing:startup_tracing",

[sky, 2015/06/18 22:18:16]

This isn't actually using statup_tracing. It's the other places that are and
should have this dep, right?

[Zhen Wang, 2015/06/18 22:37:58]

I was following the pattern in content/child/BUILD.gn to add the dependency to
common. Should I add the dependency directly to the followings?
- mojo_runner_lib in src/mojo/runner/BUILD.gn
- mandoline in mandoline/app/desktop/BUILD.gn

[sky, 2015/06/18 23:43:08]

Each step of the build should list targets it depends upon. Otherwise dependency
checking won't work correctly. So yes, put the deps where the files are
included.

[Zhen Wang, 2015/06/19 03:26:10]

Done.

     "//third_party/mojo/src/mojo/public/c/system:for_component",
   ]
 }