Add Accessibility Object Model to content features, and add a browser test.

content/child/runtime_features.cc

 // Copyright 2013 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.
 
 #include "content/child/runtime_features.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/feature_list.h"
@@ skipping 299 matching lines @@
   WebRuntimeFeatures::enableTimerThrottlingForHiddenFrames(
       base::FeatureList::IsEnabled(features::kTimerThrottlingForHiddenFrames));
 
   WebRuntimeFeatures::enableTouchpadAndWheelScrollLatching(
       base::FeatureList::IsEnabled(features::kTouchpadAndWheelScrollLatching));
 
   if (base::FeatureList::IsEnabled(
           features::kSendBeaconThrowForBlobWithNonSimpleType))
     WebRuntimeFeatures::enableSendBeaconThrowForBlobWithNonSimpleType(true);
 
+  WebRuntimeFeatures::enableAccessibilityObjectModel(
+      base::FeatureList::IsEnabled(features::kAccessibilityObjectModel));
+
 #if defined(OS_ANDROID)
   if (command_line.HasSwitch(switches::kDisableMediaSessionAPI))
     WebRuntimeFeatures::enableMediaSession(false);
 
   WebRuntimeFeatures::enablePaymentRequest(
       base::FeatureList::IsEnabled(features::kWebPayments));
 #endif
 
   // Sets the RuntimeEnabledFeatures for Navigation Preload feature only when
   // '--enable-features' command line flag is given. While experimenting this
@@ skipping 50 matching lines @@
   if (command_line.HasSwitch(switches::kDisableBlinkFeatures)) {
     std::vector<std::string> disabled_features = base::SplitString(
         command_line.GetSwitchValueASCII(switches::kDisableBlinkFeatures),
         ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
     for (const std::string& feature : disabled_features)
       WebRuntimeFeatures::enableFeatureFromString(feature, false);
   }
 }
 
 }  // namespace content