PlzNavigate: fix regression on the FYI bot.

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 0ab358f06eb7dcc20666cde8805407294848fb93..01a11f79704d5f2e9ac1902c5017fa04a31a8772 100644
--- a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
+++ b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
@@ -2016,6 +2016,7 @@ bool WebLocalFrameImpl::maybeRenderFallbackContent(
     return false;
 
   FrameLoader& frameloader = frame()->loader();
+  frameloader.clearNavigationHandledByClient();
   frameloader.loadFailed(frameloader.documentLoader(), error);
   return true;
 }