Add setting to isolate zoom changes by default.

content/browser/web_contents/web_contents_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/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 892 matching lines @@
                                    false);  // reset_state
   }
   if (browser_plugin_embedder_)
     browser_plugin_embedder_->CancelGuestDialogs();
 }
 
 void WebContentsImpl::ClosePage() {
   GetRenderViewHost()->ClosePage();
 }
 
+void WebContentsImpl::OnReplaced(WebContents* new_contents) {
+  for (auto& observer : observers_)
+    observer.WebContentsReplaced(this, new_contents);
+}
+
 RenderWidgetHostView* WebContentsImpl::GetRenderWidgetHostView() const {
   return GetRenderManager()->GetRenderWidgetHostView();
 }
 
 RenderWidgetHostView* WebContentsImpl::GetTopLevelRenderWidgetHostView() {
   if (GetOuterWebContents())
     return GetOuterWebContents()->GetTopLevelRenderWidgetHostView();
   return GetRenderManager()->GetRenderWidgetHostView();
 }
 
@@ skipping 4497 matching lines @@
   GetMainFrame()->AddMessageToConsole(
       content::CONSOLE_MESSAGE_LEVEL_WARNING,
       base::StringPrintf("This site does not have a valid SSL "
                          "certificate! Without SSL, your site's and "
                          "visitors' data is vulnerable to theft and "
                          "tampering. Get a valid SSL certificate before"
                          " releasing your website to the public."));
 }
 
 }  // namespace content