Certificate Transparency: Wire the TreeStateTracker up.

This change puts into use the TreeStateTracker class by wiring it to:
* A global STHDistributor for receiving fresh STHs via the component
  updater.
* The per-profile CTVerifier for receiving notification of verified
  SCTs that should be checked for inclusion.

As discussed with sorin and rsleevi, the wiring of the STHSetComponentInstaller
is via a globally-accessible STHDistributor, created by the IOThread.

BUG=613501

Review-Url: https://codereview.chromium.org/2014573002
Cr-Commit-Position: refs/heads/master@{#397096}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index dfc340a..f079086b 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -117,6 +117,7 @@
     "//components/browser_sync/common",
     "//components/captive_portal",
     "//components/certificate_reporting",
+    "//components/certificate_transparency",
     "//components/cloud_devices/common",
     "//components/component_updater",
     "//components/content_settings/content/common",