Move //components/test_runner back into //content/shell

This was originally moved into //components so it could be shared with
Mandoline. Since Mandoline has been removed from the tree, move this
back into //content to simplify the layering.

Mostly automated with:
git mv components/test_runner content/shell/test_runner
sed -i s/COMPONENTS_TEST_RUNNER_/CONTENT_SHELL_TEST_RUNNER_/ $(git gs COMPONENTS_TEST_RUNNER_ | cut -d: -f1 | uniq)
sed -i 's/components\/test_runner/content\/shell\/test_runner/' $(git gs "components/test_runner" | cut -d: -f1 | uniq)
git cl format

with a few manual cleanups.

BUG=585292

Review-Url: https://codereview.chromium.org/2707183003
Cr-Commit-Position: refs/heads/master@{#451976}
diff --git a/content/shell/renderer/DEPS b/content/shell/renderer/DEPS
index 8807c28..244f046 100644
--- a/content/shell/renderer/DEPS
+++ b/content/shell/renderer/DEPS
@@ -3,6 +3,6 @@
   "+components/cdm",
   "+components/web_cache/renderer",
   "+components/plugins/renderer",
-  "+components/test_runner",
+  "+content/shell/test_runner",
   "+services/service_manager/public/cpp",
 ]