Change PageTest.WillStartBrowser to depend on platform instead of browser object as it would not ha…

tools/perf/measurements/smoothness_unittest.py

 # Copyright 2013 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.
 import sys
 
 from measurements import smoothness
 from metrics import power
 from telemetry.core import exceptions
 from telemetry.core import wpr_modes
 from telemetry.page import page
@@ skipping 50 matching lines @@
   def testSyntheticDelayConfiguration(self):
     test_page = page.Page('http://dummy', None)
     test_page.synthetic_delays = {
         'cc.BeginMainFrame': { 'target_duration': 0.012 },
         'cc.DrawAndSwap': { 'target_duration': 0.012, 'mode': 'alternating' },
         'gpu.PresentingFrame': { 'target_duration': 0.012 }
     }
 
     tab = FakeTab()
     measurement = smoothness.Smoothness()
-    measurement.WillStartBrowser(tab.browser)
+    measurement.WillStartBrowser(tab.browser.platform)
     measurement.WillNavigateToPage(test_page, tab)
     measurement.WillRunActions(test_page, tab)
 
     expected_category_filter = set([
         'DELAY(cc.BeginMainFrame;0.012000;static)',
         'DELAY(cc.DrawAndSwap;0.012000;alternating)',
         'DELAY(gpu.PresentingFrame;0.012000;static)',
         'benchmark'
     ])
     tracing_controller = tab.browser.platform.tracing_controller
@@ skipping 77 matching lines @@
         self.start_called = True
       def Stop(self, _1, _2):
         self.stop_called = True
 
     ps = self.CreateEmptyPageSet()
     ps.AddPage(FailPage(ps))
 
     class BuggyMeasurement(smoothness.Smoothness):
       fake_power = None
       # Inject fake power metric.
-      def WillStartBrowser(self, browser):
-        self.fake_power = self._power_metric = FakePowerMetric(browser)
+      def WillStartBrowser(self, platform):
+        self.fake_power = self._power_metric = FakePowerMetric(platform)
 
     measurement = BuggyMeasurement()
     try:
       self.RunMeasurement(measurement, ps)
     except page_test.TestNotSupportedOnPlatformFailure:
       pass
 
     self.assertTrue(measurement.fake_power.start_called)
     self.assertTrue(measurement.fake_power.stop_called)