Escape all of invalid values in console messages for INPUT elements.

Source/core/html/forms/DateInputType.cpp

Index: Source/core/html/forms/DateInputType.cpp
diff --git a/Source/core/html/forms/DateInputType.cpp b/Source/core/html/forms/DateInputType.cpp
index fb687f3bd1abd9bc1ed7d80c0ef302dd50beab10..91732e395345cea320b08c548bb211d200e93874 100644
--- a/Source/core/html/forms/DateInputType.cpp
+++ b/Source/core/html/forms/DateInputType.cpp
@@ -38,6 +38,7 @@
 #include "core/html/forms/DateTimeFieldsState.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "platform/DateComponents.h"
+#include "platform/JSONValues.h"
 #include "platform/text/PlatformLocale.h"
 #include "wtf/PassOwnPtr.h"
 
@@ -94,7 +95,7 @@ void DateInputType::warnIfValueIsInvalid(const String& value) const
 {
     if (value != element().sanitizeValue(value)) {
         element().document().addConsoleMessage(ConsoleMessage::create(RenderingMessageSource, WarningMessageLevel,
-            String::format("The specified value '%s' does not conform to the required format, 'yyyy-MM-dd'.", value.utf8().data())));
+            String::format("The specified value %s does not conform to the required format, \"yyyy-MM-dd\".", JSONValue::quoteString(value).utf8().data())));
     }
 }