PlzNavigate: Allow frames to fallback to alternative content.

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

Index: third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
index 6b79f108391b9673c12b354a0056d91d34a2b09f..3e737ac88d41f2b58d5cc22ab77f931dd93e31e7 100644
--- a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
+++ b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
@@ -2057,6 +2057,12 @@ void WebLocalFrameImpl::loadData(const WebData& data,
       static_cast<HistoryLoadType>(webHistoryLoadType));
 }
 
+void WebLocalFrameImpl::didFailNavigation() {
+  DCHECK(frame());
+  if (frame()->owner())

[arthursonzogni, 2016/10/21 15:59:31]

I don't know if I can assume that frame()->owner() will always be non-null and
replace the "if" with a "DCHECK".

+    frame()->owner()->renderFallbackContent();
+}
+
 bool WebLocalFrameImpl::isLoading() const {
   if (!frame() || !frame()->document())
     return false;