PlzNavigate: Do not send synchronous navigations from the renderer to the browser.

content/renderer/render_frame_impl.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/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 4311 matching lines @@
       info.defaultPolicy == blink::WebNavigationPolicyCurrentTab &&
       // Must be a JavaScript navigation, which appears as "other".
       info.navigationType == blink::WebNavigationTypeOther;
 
   if (is_fork) {
     // Open the URL via the browser, not via WebKit.
     OpenURL(info.frame, url, Referrer(), info.defaultPolicy);
     return blink::WebNavigationPolicyIgnore;
   }
 
-  // PlzNavigate: send the request to the browser if needed.
+  // PlzNavigate: if the navigation is not synchronous, send it to the browser.
+  // This includes navigations with no request being sent to the network stack.
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableBrowserSideNavigation) &&
-      info.urlRequest.checkForBrowserSideNavigation()) {
+      info.urlRequest.checkForBrowserSideNavigation() &&
+      ShouldMakeNetworkRequestForURL(url)) {
     BeginNavigation(&info.urlRequest);
     return blink::WebNavigationPolicyIgnore;
   }
 
   return info.defaultPolicy;
 }
 
 void RenderFrameImpl::OpenURL(WebFrame* frame,
                               const GURL& url,
                               const Referrer& referrer,
@@ skipping 656 matching lines @@
         cdm_manager_
 #endif
         ));
 #endif  //  defined(ENABLE_MOJO_MEDIA)
   }
 
   return cdm_factory_.get();
 }
 
 }  // namespace content