chromeos: Improve ProxyResolutionServiceProvider testing.

chrome/browser/chromeos/dbus/chrome_proxy_resolver_delegate.cc

Index: chrome/browser/chromeos/dbus/chrome_proxy_resolver_delegate.cc
diff --git a/chrome/browser/chromeos/dbus/chrome_proxy_resolver_delegate.cc b/chrome/browser/chromeos/dbus/chrome_proxy_resolver_delegate.cc
index c853ace4322f523abe75d360d9f3f006d74324f6..ac8874a344786fcd2ce8febe1c48aeaf7358ecf3 100644
--- a/chrome/browser/chromeos/dbus/chrome_proxy_resolver_delegate.cc
+++ b/chrome/browser/chromeos/dbus/chrome_proxy_resolver_delegate.cc
@@ -5,6 +5,8 @@
 #include "chrome/browser/chromeos/dbus/chrome_proxy_resolver_delegate.h"
 
 #include "chrome/browser/profiles/profile_manager.h"
+#include "net/log/net_log_with_source.h"
+#include "net/proxy/proxy_service.h"
 #include "net/url_request/url_request_context_getter.h"
 
 namespace chromeos {
@@ -19,4 +21,15 @@ ChromeProxyResolverDelegate::GetRequestContext() {
   return profile->GetRequestContext();
 }
 
+int ChromeProxyResolverDelegate::ResolveProxy(
+    net::ProxyService* proxy_service,
+    const GURL& url,
+    net::ProxyInfo* results,
+    const net::CompletionCallback& callback) {
+  DCHECK(proxy_service);
+  DCHECK(results);
+  return proxy_service->ResolveProxy(url, std::string(), results, callback,
+                                     nullptr, nullptr, net::NetLogWithSource());
+}
+
 }  // namespace chromeos