PlzNavigate: make MHTML iframe load working.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 2b20d2bba3a59d5a0a399f4fb0b09aeaa13d09c5..abc90002fa543e6cc7d648268326ce96cc8184bc 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -5598,11 +5598,17 @@ WebNavigationPolicy RenderFrameImpl::DecidePolicyForNavigation(
     }
   }
 
+  // When an MHTML Archive is present, it should be used to serve iframe content
+  // instead of doing a network request.
+  bool use_archive =
+      (info.archive_status == NavigationPolicyInfo::ArchiveStatus::Present) &&
+      !url.SchemeIs(url::kDataScheme);
+
   // 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 (IsBrowserSideNavigationEnabled() &&
       info.url_request.CheckForBrowserSideNavigation() &&
-      ShouldMakeNetworkRequestForURL(url)) {
+      ShouldMakeNetworkRequestForURL(url) && !use_archive) {

[nasko, 2017/05/03 17:28:39]

I'm not sure I follow why we should be sending "cid:Something" requests to the
network stack. Since we don't expect them outside of MHTML, shouldn't we have a
simple check that says "if !archive && cid, return ignore" (or if there is a
better policy value)?

[arthursonzogni, 2017/05/04 14:26:32]

See my first answer above.

     if (info.default_policy == blink::kWebNavigationPolicyCurrentTab) {
       // The BeginNavigation() call happens in didStartProvisionalLoad(). We
       // need to save information about the navigation here.