Add a warning for the deprecation of content-initiated data URL navigations

content/browser/frame_host/navigation_handle_impl.cc

 // Copyright 2015 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/frame_host/navigation_handle_impl.h"
 
 #include <iterator>
 
 #include "base/debug/dump_without_crashing.h"
 #include "base/logging.h"
@@ skipping 136 matching lines @@
 NavigationHandleImpl::~NavigationHandleImpl() {
   // Transfer requests that have not matched up with another navigation request
   // from the renderer need to be cleaned up. These are marked as protected in
   // the RDHI, so they do not get cancelled when frames are destroyed.
   if (is_transferring()) {
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(&NotifyAbandonedTransferNavigation, GetGlobalRequestID()));
   }
 
+  if (url_.SchemeIs(url::kDataScheme) && IsInMainFrame() &&

[Charlie Reis, 2017/02/15 23:36:43]

Why is this done from the NavigationHandleImpl destructor?  The test failures
seem to indicate that it's not safe to call GetRenderFrameHost() from there.

Maybe it would be better to do this somewhere related to the navigation commit
instead, like DidCommitNavigation?

[meacer, 2017/02/16 01:58:42]

Done, moved to DidCommitNavigation.

+      IsRendererInitiated()) {
+    GetRenderFrameHost()->AddMessageToConsole(
+        CONSOLE_MESSAGE_LEVEL_WARNING,
+        "Upcoming versions will block content-initiated top frame navigations "
+        "to data: URLs. For more information, see https://crbug.com/594215.");

[Charlie Reis, 2017/02/15 23:36:43]

This bug link doesn't seem like great documentation for people to reference. 
There's not much discussion of the reasoning or alternatives there, and it has a
link to a Google internal design doc (http://go/crbug-pseudo-urls).  Is there a
better link we can provide to developers?  Or maybe update the description of
that bug to provide a better overview?

[meacer, 2017/02/16 01:58:42]

Do you think blink intent to deprecate thread would be more useful? I can add a
goo.gl version of
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/GbVcuwg_QjM

I think it has the most complete context about this, and also has links to
tracking bugs and the feature dashboard.

[Charlie Reis, 2017/02/16 17:59:50]

Yes, a link to that intent would be perfect.  Thanks!

+  }
+
   if (!IsRendererDebugURL(url_))
     GetDelegate()->DidFinishNavigation(this);
 
   // Cancel the navigation on the IO thread if the NavigationHandle is being
   // destroyed in the middle of the NavigationThrottles checks.
   if (!IsBrowserSideNavigationEnabled() && !complete_callback_.is_null())
     RunCompleteCallback(NavigationThrottle::CANCEL_AND_IGNORE);
 
   if (IsInMainFrame()) {
     TRACE_EVENT_ASYNC_END2("navigation", "Navigation StartToCommit", this,
@@ skipping 716 matching lines @@
       content::AncestorThrottle::MaybeCreateThrottleFor(this);
   if (ancestor_throttle)
     throttles_.push_back(std::move(ancestor_throttle));
 
   throttles_.insert(throttles_.begin(),
                     std::make_move_iterator(throttles_to_register.begin()),
                     std::make_move_iterator(throttles_to_register.end()));
 }
 
 }  // namespace content