Don't show "Service Worker Fallback Required" error message in DevTools console.

Source/core/frame/FrameConsole.cpp

Index: Source/core/frame/FrameConsole.cpp
diff --git a/Source/core/frame/FrameConsole.cpp b/Source/core/frame/FrameConsole.cpp
index b2e5e4157dfdf595116bac630dd30e57a69d7fb7..46110516abda3f05e3727ddcfa5257f0bc5e306a 100644
--- a/Source/core/frame/FrameConsole.cpp
+++ b/Source/core/frame/FrameConsole.cpp
@@ -129,6 +129,8 @@ void FrameConsole::reportResourceResponseReceived(DocumentLoader* loader, unsign
         return;
     if (response.httpStatusCode() < 400)
         return;
+    if (response.wasFallbackRequiredByServiceWorker())
+        return;
     String message = "Failed to load resource: the server responded with a status of " + String::number(response.httpStatusCode()) + " (" + response.httpStatusText() + ')';
     RefPtrWillBeRawPtr<ConsoleMessage> consoleMessage = ConsoleMessage::create(NetworkMessageSource, ErrorMessageLevel, message, response.url().string());
     consoleMessage->setRequestIdentifier(requestIdentifier);