Add a warning whenever link preloads are not used

third_party/WebKit/Source/core/loader/FrameFetchContext.cpp

Index: third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp b/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
index a11afccdaa3ea0d81ba86bf8c8f0d604fc2c358e..fbb533a94e02385615b497c669072271d5cf81b5 100644
--- a/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
@@ -654,10 +654,13 @@ void FrameFetchContext::sendImagePing(const KURL& url)
     PingLoader::loadImage(frame(), url);
 }
 
-void FrameFetchContext::addConsoleMessage(const String& message) const
+void FrameFetchContext::addConsoleMessage(const String& message, LogMessageType messageType) const
 {
+    MessageLevel level = ErrorMessageLevel;
+    if (messageType == LogWarningMessage)
+        level = WarningMessageLevel;
     if (frame()->document())
-        frame()->document()->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, message));
+        frame()->document()->addConsoleMessage(ConsoleMessage::create(JSMessageSource, level, message));
 }
 
 SecurityOrigin* FrameFetchContext::getSecurityOrigin() const