Provision to start base::SimpleTestTickClock at initial ticks

cc/surfaces/display_scheduler_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 "cc/surfaces/display_scheduler.h"
 
 #include "base/logging.h"
 #include "base/test/null_task_runner.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 52 matching lines @@
   }
 
  protected:
   int scheduler_begin_frame_deadline_count_;
 };
 
 class DisplaySchedulerTest : public testing::Test {
  public:
   DisplaySchedulerTest() : now_src_(new base::SimpleTestTickClock()) {
     const int max_pending_swaps = 1;
-    now_src_->Advance(base::TimeDelta::FromMicroseconds(10000));
     null_task_runner_ = make_scoped_refptr(new base::NullTaskRunner);
     client_ = make_scoped_ptr(new FakeDisplaySchedulerClient);
     scheduler_ = make_scoped_ptr(
         new TestDisplayScheduler(client_.get(), &fake_begin_frame_source_,
                                  null_task_runner_, max_pending_swaps));
   }
 
   ~DisplaySchedulerTest() override {}
 
   void SetUp() override { scheduler_->SetRootSurfaceResourcesLocked(false); }
@@ skipping 251 matching lines @@
 
   scheduler_->SetRootSurfaceResourcesLocked(true);
   EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());
 
   scheduler_->OutputSurfaceLost();
   EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());
 }
 
 }  // namespace
 }  // namespace cc