Add option to force document level passive event listeners as a runtime feature.

content/renderer/render_view_impl.cc

 // 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.
 
 #include "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <memory>
 
@@ skipping 728 matching lines @@
           switches::kTouchTextSelectionStrategy);
   if (selection_strategy_str == "direction")
     selection_strategy = WebSettings::SelectionStrategyType::Direction;
   webview()->settings()->setSelectionStrategy(selection_strategy);
 
   std::string passiveListenersDefault =
       command_line.GetSwitchValueASCII(switches::kPassiveListenersDefault);
   if (!passiveListenersDefault.empty()) {
     WebSettings::PassiveEventListenerDefault passiveDefault =
         WebSettings::PassiveEventListenerDefault::False;
-    if (passiveListenersDefault == "documentonlytrue")
-      passiveDefault = WebSettings::PassiveEventListenerDefault::DocumentTrue;
-    else if (passiveListenersDefault == "true")
+    if (passiveListenersDefault == "true")
       passiveDefault = WebSettings::PassiveEventListenerDefault::True;
     else if (passiveListenersDefault == "forcealltrue")
       passiveDefault = WebSettings::PassiveEventListenerDefault::ForceAllTrue;
     webview()->settings()->setPassiveEventListenerDefault(passiveDefault);
   }
 
   ApplyBlinkSettings(command_line, webview()->settings());
 
   if (params.main_frame_routing_id != MSG_ROUTING_NONE) {
     main_render_frame_ = RenderFrameImpl::CreateMainFrame(
@@ skipping 2499 matching lines @@
         return render_frame->focused_pepper_plugin();
     }
     frame = frame->traverseNext(false);
   }
 
   return nullptr;
 }
 #endif
 
 }  // namespace content