Remove net-internals page for throttling, introduce flag for extension devs instead.

chrome/test/data/webui/net_internals/log_util.js

 // Copyright (c) 2012 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.
 
 /**
  * @fileoverview This file contains tests for creating and loading log files.
  * It also tests the stop capturing button, since it both creates and then loads
  * a log dump.
  */
 
@@ skipping 92 matching lines @@
     export: true,
     import: true,
     proxy: true,
     events: true,
     timeline: true,
     dns: true,
     sockets: true,
     spdy: true,
     httpPipeline: false,
     httpCache: true,
-    httpThrottling: false,
     serviceProviders: cr.isWindows,
     tests: false,
     hsts: false,
     logs: false,
     prerender: true,
     chromeos: false
   };
   NetInternalsTest.checkTabHandleVisibility(tabVisibilityState, false);
 }
 
@@ skipping 61 matching lines @@
   taskQueue.addFunctionTask(checkViewsAfterLogLoaded);
   taskQueue.addTask(new CreateAndLoadLogTask('Detailed explanation.'));
   taskQueue.addFunctionTask(checkViewsAfterLogLoaded);
   taskQueue.run();
 
   // Simulate a click on the stop capturing button.
   $(CaptureStatusView.STOP_BUTTON_ID).click();
 });
 
 })();  // Anonymous namespace