Added completion notification to Profile's ClearNetworkingHistorySince.

chrome/test/base/testing_profile.cc

Index: chrome/test/base/testing_profile.cc
diff --git a/chrome/test/base/testing_profile.cc b/chrome/test/base/testing_profile.cc
index 7365b74bc6361465433c2704368de236519ced28..a41d56575d882457b693903b626f5960fe582cfb 100644
--- a/chrome/test/base/testing_profile.cc
+++ b/chrome/test/base/testing_profile.cc
@@ -762,8 +762,12 @@ chrome_browser_net::Predictor* TestingProfile::GetNetworkPredictor() {
   return NULL;
 }
 
-void TestingProfile::ClearNetworkingHistorySince(base::Time time) {
-  NOTIMPLEMENTED();
+void TestingProfile::ClearNetworkingHistorySince(
+    base::Time time,
+    const base::Closure& completion) {
+  if (!completion.is_null()) {
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, completion);
+  }
 }
 
 GURL TestingProfile::GetHomePage() {