headless: Also build the headless shell target on the bot

testing/buildbot/chromium.fyi.json

Index: testing/buildbot/chromium.fyi.json
diff --git a/testing/buildbot/chromium.fyi.json b/testing/buildbot/chromium.fyi.json
index d528804a52ea29fa512e106f8c1bb6b4a1c59271..0a4d0c60fcbf267949ff73f5c702a3957ef32c23 100644
--- a/testing/buildbot/chromium.fyi.json
+++ b/testing/buildbot/chromium.fyi.json
@@ -9002,6 +9002,7 @@
   "Headless Linux (dbg)": {
     "additional_compile_targets": [
       "headless_lib",
+      "headless_shell",

[Ken Russell (switch to Gerrit), 2016/08/15 20:26:56]

In general it would be better for this to be built as a dependency of one of the
test targets that are run on this machine. Is that the long-term plan?

[Sami, 2016/08/16 09:40:58]

The problem is that none of the headless unit or browser tests actually need the
headless shell app to run; it's more of an interactive tool for developers. The
app will ultimately go away once we teach Chrome itself to become headless, but
for now it's useful to have around.

       "headless_tests"
     ],
     "gtest_tests": [