Use estimated vsync period on Android

content/public/android/javatests/src/org/chromium/content/browser/VSyncMonitorTest.java

 // Copyright 2012 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.
 
 package org.chromium.content.browser;
 
 import android.content.Context;
 import android.os.SystemClock;
 import android.test.InstrumentationTestCase;
 import android.test.suitebuilder.annotation.MediumTest;
+import android.view.WindowManager;
 
 import org.chromium.base.ThreadUtils;
 import org.chromium.ui.VSyncMonitor;
 
 import java.util.Arrays;
 import java.util.concurrent.Callable;
 
 /**
  * Tests VSyncMonitor to make sure it generates correct VSync timestamps.
  */
@@ skipping 80 matching lines @@
 
         // Check that the median frame rate is within 10% of the reported frame period.
         assertTrue(collector.mFrameCount == totalFrames - 1);
         Arrays.sort(collector.mFramePeriods, 0, collector.mFramePeriods.length);
         long medianFramePeriod = collector.mFramePeriods[collector.mFramePeriods.length / 2];
         if (Math.abs(medianFramePeriod - reportedFramePeriod) > reportedFramePeriod * .1) {
             fail("Measured median frame period " + medianFramePeriod
                     + " differs by more than 10% from the reported frame period "
                     + reportedFramePeriod + " for requested frames");
         }
+
+        if (enableJBVSync) {
+            Context context = getInstrumentation().getContext();
+            float refreshRate = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE))
+                .getDefaultDisplay().getRefreshRate();
+            if (refreshRate < 30.0f) {
+                // Reported refresh rate is most likely incorrect.
+                // Estimated vsync period is expected to be lower than (1000000 / 30) microseconds
+                assertTrue(monitor.getVSyncPeriodInMicroseconds() < 1000000 / 30);
+            }
+        }
     }
 
     // Check that the vsync period roughly matches the timestamps that the monitor generates.
     @MediumTest
     public void testVSyncPeriodAllowJBVSync() throws InterruptedException {
         performVSyncPeriodTest(true);
     }
 
     // Check that the vsync period roughly matches the timestamps that the monitor generates.
     @MediumTest
@@ skipping 20 matching lines @@
     @MediumTest
     public void testVSyncActivationFromIdleAllowJBVSync() throws InterruptedException {
         performVSyncActivationFromIdle(true);
     }
 
     @MediumTest
     public void testVSyncActivationFromIdleDisallowJBVSync() throws InterruptedException {
         performVSyncActivationFromIdle(false);
     }
 }