Provision to start base::SimpleTestTickClock at initial ticks

chrome/browser/android/data_usage/data_use_tab_model_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/data_usage/data_use_tab_model.h"
 
 #include <stdint.h>
 
 #include <string>
 
@@ skipping 61 matching lines @@
 
  protected:
   void SetUp() override {
     base::RunLoop().RunUntilIdle();
     data_use_tab_model_.reset(new DataUseTabModel());
     data_use_tab_model_->InitOnUIThread(
         content::BrowserThread::GetMessageLoopProxyForThread(
             content::BrowserThread::IO),
         base::WeakPtr<ExternalDataUseObserver>());
 
-    tick_clock_ = new base::SimpleTestTickClock();
-
-    // Advance to non nil time.
-    tick_clock_->Advance(base::TimeDelta::FromSeconds(1));
+    // Start at a non nil time.
+    tick_clock_ = new base::SimpleTestTickClock(
+        base::TimeTicks() + base::TimeDelta::FromSeconds(1));
 
     // |tick_clock_| will be owned by |data_use_tab_model_|.
     data_use_tab_model_->tick_clock_.reset(tick_clock_);
   }
 
   // Returns true if tab entry for |tab_id| exists in |active_tabs_|.
   bool IsTabEntryExists(SessionID::id_type tab_id) const {
     return data_use_tab_model_->active_tabs_.find(tab_id) !=
            data_use_tab_model_->active_tabs_.end();
   }
@@ skipping 702 matching lines @@
   labels.push_back("label_4");
   labels.push_back("label_5");
   RegisterURLRegexes(std::vector<std::string>(labels.size(), std::string()),
                      std::vector<std::string>(labels.size(), kURLFoo), labels);
   EXPECT_FALSE(IsTrackingDataUse(kTabID1));
 }
 
 }  // namespace android
 
 }  // namespace chrome