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 63eab1b5640d4241d6d69afacbdde8714495f23d..4bf6eac7d2c0c654ac3de4e4eec8e7d4f69ead4c 100644
--- a/chrome/test/base/testing_profile.cc
+++ b/chrome/test/base/testing_profile.cc
@@ -784,8 +784,12 @@ 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() {