PlzNavigate: Enforce 'form-action' CSP on the browser-side.

third_party/WebKit/Source/core/loader/FrameLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) Research In Motion Limited 2009. All rights reserved.
  * Copyright (C) 2011 Kris Jordan <krisjordan@gmail.com>
  * Copyright (C) 2011 Google Inc. All rights reserved.
@@ skipping 1644 matching lines @@
         m_frame->document()->enforceSandboxFlags(SandboxOrigin);
         m_frame->owner()->dispatchLoad();
         return NavigationPolicyIgnore;
       }
     }
   }
 
   bool isFormSubmission = type == NavigationTypeFormSubmitted ||
                           type == NavigationTypeFormResubmitted;
   if (isFormSubmission &&
+      // 'form-action' check in the frame that is navigating is disabled on the
+      // renderer side when PlzNavigate is enabled, but is enforced on the
+      // browser side instead.
+      // N.B. check in the frame that initiate the navigation stills occurs in
+      // blink and is not enforced on the browser-side.
+      // See https://crbug.com/700964
+      !browserSideNavigationEnabled &&

[Mike West, 2017/03/14 15:45:39]

I'm fine with leaving this in, as long as we figure out a solution for the small
regression. I'm also fine if you'd prefer to drop it and rely on the existing
renderer-side behavior so that PlzNavigate can ship more quickly. Either way,
please leave the TODO and link to the bug. :)

[arthursonzogni, 2017/03/15 13:15:09]

Done. BUG and TODO added.

       !m_frame->document()->contentSecurityPolicy()->allowFormAction(
           request.url()))
     return NavigationPolicyIgnore;
 
   bool replacesCurrentHistoryItem =
       frameLoadType == FrameLoadTypeReplaceCurrentItem;
   policy = client()->decidePolicyForNavigation(
       request, loader, type, policy, replacesCurrentHistoryItem,
       isClientRedirect, form, shouldCheckMainWorldContentSecurityPolicy);
   if (policy == NavigationPolicyCurrentTab ||
@@ skipping 315 matching lines @@
       frameLoadRequest.clientRedirect());
 
   loader->setLoadType(loadType);
   loader->setNavigationType(navigationType);
   loader->setReplacesCurrentHistoryItem(loadType ==
                                         FrameLoadTypeReplaceCurrentItem);
   return loader;
 }
 
 }  // namespace blink