Create and integrate a metrics service client into Blimp engine.

blimp/engine/session/blimp_engine_session.cc

Index: blimp/engine/session/blimp_engine_session.cc
diff --git a/blimp/engine/session/blimp_engine_session.cc b/blimp/engine/session/blimp_engine_session.cc
index 06f1faf1c4d105fb3b0a0b55079377acebb2e769..0fe3377ed40ba4254d9f85f59de2c725ad322b8f 100644
--- a/blimp/engine/session/blimp_engine_session.cc
+++ b/blimp/engine/session/blimp_engine_session.cc
@@ -260,6 +260,8 @@ void BlimpEngineSession::Initialize() {
 
   RegisterFeatures();
 
+  browser_context_->Initialize();
+
   // Initialize must only be posted after the RegisterFeature calls have
   // completed.
   content::BrowserThread::PostTask(
@@ -269,6 +271,9 @@ void BlimpEngineSession::Initialize() {
                  engine_config_->client_token()));
 }
 
+void BlimpEngineSession::Finalize() {
+  browser_context_->Finalize();
+}

[Bernhard Bauer, 2016/04/25 08:21:36]

Nit: empty line after this one.

[Jess, 2016/04/26 00:01:25]

Done.

 void BlimpEngineSession::RegisterFeatures() {
   thread_pipe_manager_.reset(new ThreadPipeManager(
       content::BrowserThread::GetMessageLoopProxyForThread(