Create errors (especially cancellation errors) internally to WebCore, rather

Source/Platform/chromium/src/Platform.cpp

Index: Source/Platform/chromium/src/Platform.cpp
===================================================================
--- Source/Platform/chromium/src/Platform.cpp	(revision 148844)
+++ Source/Platform/chromium/src/Platform.cpp	(working copy)
@@ -31,6 +31,8 @@
 #include "config.h"
 #include <public/Platform.h>
 
+#include <public/WebURLError.h>
+
 namespace WebKit {
 
 static Platform* s_platform = 0;
@@ -50,4 +52,12 @@
     return s_platform;
 }
 
+WebURLError Platform::cancelledError(const WebURL& unreachableURL) const
+{
+    WebURLError error;
+    error.unreachableURL = unreachableURL;
+    error.isCancellation = true;
+    return error;
+}
+
 } // namespace WebKit