Migrate TabControlFeature from 0.5 to 0.6

blimp/client/public/BUILD.gn

 # Copyright 2016 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.
 
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
 }
 
 # Only //chrome should ever depend on this. Code in //blimp/client/* should
@@ skipping 12 matching lines @@
 # All code in //blimp/client/* should depend on this target instead of
 # //blimp/client/public to ensure there are no circular dependencies or
 # duplicate symbols regardless of whether enable_blimp_client is set or not.
 source_set("public_headers") {
   visibility = [ "//blimp/client/*" ]
 
   sources = [
     "blimp_client_context.h",
     "blimp_client_context_delegate.h",
     "contents/blimp_contents.h",
+    "contents/blimp_contents_observer.cc",
     "contents/blimp_contents_observer.h",
     "contents/blimp_navigation_controller.h",
   ]
 
   public_deps = [
     "//base",
     "//components/keyed_service/core",
     "//url",
   ]
 
@@ skipping 27 matching lines @@
       "android/java/src/org/chromium/blimp_public/contents/BlimpContents.java",
       "android/java/src/org/chromium/blimp_public/contents/BlimpContentsObserver.java",
       "android/java/src/org/chromium/blimp_public/contents/BlimpNavigationController.java",
       "android/java/src/org/chromium/blimp_public/contents/EmptyBlimpContentsObserver.java",
       "android/java/src/org/chromium/blimp_public/BlimpClientContext.java",
       "android/java/src/org/chromium/blimp_public/BlimpClientContextDelegate.java",
       "android/java/src/org/chromium/blimp_public/BlimpSettingsCallbacks.java",
     ]
   }
 }