blimp: Update page load status update indicator to use first paint.

blimp/engine/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//tools/grit/repack.gni")
 import("//tools/grit/grit_rule.gni")
@@ skipping 232 matching lines @@
     "//third_party/libwebp",
     "//ui/gfx/geometry",
     "//ui/gl",
   ]
 }
 
 source_set("session") {
   sources = [
     "session/blimp_engine_session.cc",
     "session/blimp_engine_session.h",
+    "session/page_load_tracker.cc",
+    "session/page_load_tracker.h",
   ]
 
   deps = [
     ":app_config",
     ":app_settings",
     ":app_switches",
     ":app_ui",
     ":common",
     ":feature",
     "//base",
@@ skipping 149 matching lines @@
       _rebased_dockerfile,
       "--startup-script",
       _rebased_startup_script,
       "--manifest",
       _rebased_manifest,
       "--output",
       rebase_path(_bundle),
     ]
   }
 }