Fix a crash when processing an invalid PAC script.

net/data/proxy_resolver_v8_unittest/exception_findproxyforurl_during_init.js

+// This PAC script will throw an exception when accessing the
+// "FindProxyForURL" property.
+
+function FindProxyForURLGetter() {

[mmenke, 2015/02/20 22:15:05]

nit:  f should be lowercase, I believe.

[eroman, 2015/02/20 22:24:23]

In my mind "FindProxyForURL" is the target object, so appending "Getter" should
not modify the first letter.

That said I am fine applying either change!

+  throw "crash!";
+}
+
+Object.defineProperty(this, "FindProxyForURL", {get: FindProxyForURLGetter});