athena: Avoid initializaing chromeos::Network for tests.

Initializaing chromeos::Network triggers a whole bunch of things that are
not necessary or useful in tests. So avoid initializing this subsystem, since
none of the tests depend on it. Tests that do depend on this in the future
should explicitly initialize this from SetUp().

This change brings down the runtime of athena_unittests significantly.

BUG=412535
R=oshima@chromium.org

Review URL: https://codereview.chromium.org/653853004

Cr-Commit-Position: refs/heads/master@{#300491}

athena/system/status_icon_container_view.cc

@@ -224,6 +224,7 @@ StatusIconContainerView::StatusIconContainerView(
   AddChildView(CreateLabel(color_scheme, "Network:"));
   views::Label* network_label = CreateLabel(color_scheme, std::string());
   AddChildView(network_label);
+  if (chromeos::NetworkHandler::IsInitialized())
     network_status_.reset(new NetworkStatus(network_label));
 
   views::ImageView* battery_view = new views::ImageView();

athena/test/base/athena_test_helper.cc

@@ -15,7 +15,6 @@
 #include "base/run_loop.h"
 #include "base/threading/thread.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
-#include "chromeos/network/network_handler.h"
 #include "ui/aura/env.h"
 #include "ui/aura/input_state_lookup.h"
 #include "ui/aura/test/env_test_helper.h"
@@ -52,7 +51,6 @@ void AthenaTestHelper::SetUp(ui::ContextFactory* context_factory) {
   file_thread_->StartWithOptions(options);
 
   chromeos::DBusThreadManager::Initialize();
-  chromeos::NetworkHandler::Initialize();
   ui::InitializeInputMethodForTesting();
   aura::Env::CreateInstance(true);
   aura::Env::GetInstance()->set_context_factory(context_factory);
@@ -81,7 +79,6 @@ void AthenaTestHelper::TearDown() {
 #endif
 
   ui::ShutdownInputMethodForTesting();
-  chromeos::NetworkHandler::Shutdown();
   chromeos::DBusThreadManager::Shutdown();
 }