Add a chrome://webapks page.

chrome/browser/BUILD.gn

 # Copyright 2014 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/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 4028 matching lines @@
       "../android/java/src/org/chromium/chrome/browser/tabmodel/SingleTabModel.java",
       "../android/java/src/org/chromium/chrome/browser/tabmodel/TabModelJniBridge.java",
       "../android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorBase.java",
       "../android/java/src/org/chromium/chrome/browser/toolbar/ToolbarModel.java",
       "../android/java/src/org/chromium/chrome/browser/util/ChromeContextUtil.java",
       "../android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java",
       "../android/java/src/org/chromium/chrome/browser/util/PlatformUtil.java",
       "../android/java/src/org/chromium/chrome/browser/util/UrlUtilities.java",
       "../android/java/src/org/chromium/chrome/browser/webapps/AddToHomescreenManager.java",
       "../android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java",
+      "../android/java/src/org/chromium/chrome/browser/webapps/WebApkInfoCallback.java",
       "../android/java/src/org/chromium/chrome/browser/webapps/WebApkInstaller.java",
       "../android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateDataFetcher.java",
       "../android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java",
       "../android/java/src/org/chromium/chrome/browser/webapps/WebappRegistry.java",
     ]
 
     # Used for testing only, should not be shipped to end users.
     if (!is_official_build) {
       sources += [ "../android/java/src/org/chromium/chrome/browser/offlinepages/evaluation/OfflinePageEvaluationBridge.java" ]
     }
@@ skipping 417 matching lines @@
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }
 
 service_manifest("preferences_manifest") {
   name = "preferences"
   source = "prefs/preferences_manifest.json"
 }