Add VR Shell image diff instrumentation tests

Adds basic image diffing capabilities to the VR Shell instrumentation tests
and adds image diffing versions of the enter/exit VR mode tests. Will require
adding new reference images as more devices with different resolutions are
tested (currently only has 2560 x 1440).

BUG=

Review-Url: https://codereview.chromium.org/2455683002
Cr-Commit-Position: refs/heads/master@{#435038}

chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/VrShellTest.java

@@ -7,18 +7,25 @@ package org.chromium.chrome.browser.vr_shell;
 import static org.chromium.chrome.test.util.ChromeRestriction.RESTRICTION_TYPE_DAYDREAM;
 import static org.chromium.chrome.test.util.ChromeRestriction.RESTRICTION_TYPE_NON_DAYDREAM;
 
-import android.os.SystemClock;
+import android.content.pm.ActivityInfo;
 import android.test.suitebuilder.annotation.MediumTest;
 
 import org.chromium.base.ThreadUtils;
+import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.Restriction;
 import org.chromium.chrome.test.ChromeTabbedActivityTestBase;
+import org.chromium.chrome.test.util.RenderUtils.ViewRenderer;
+
+import java.io.IOException;
 
 /**
  * Instrumentation tests for VR Shell (Chrome VR)
  */
 public class VrShellTest extends ChromeTabbedActivityTestBase {
+    private static final String GOLDEN_DIR =
+            "chrome/test/data/android/render_tests";
     private VrShellDelegate mDelegate;
+    private ViewRenderer mViewRenderer;
 
     @Override
     protected void setUp() throws Exception {
@@ -29,6 +36,8 @@ public class VrShellTest extends ChromeTabbedActivityTestBase {
     @Override
     public void startMainActivity() throws InterruptedException {
         startMainActivityOnBlankPage();
+        mViewRenderer = new ViewRenderer(getActivity(),
+                GOLDEN_DIR, this.getClass().getSimpleName());
     }
 
     private void forceEnterVr() {
@@ -51,8 +60,7 @@ public class VrShellTest extends ChromeTabbedActivityTestBase {
 
     private void testEnterExitVrMode(boolean supported) {
         forceEnterVr();
-        // TODO(bsheedy): Remove sleep once crbug.com/644533 is fixed
-        SystemClock.sleep(1500);
+        getInstrumentation().waitForIdleSync();
         if (supported) {
             assertTrue(mDelegate.isInVR());
         } else {
@@ -62,6 +70,42 @@ public class VrShellTest extends ChromeTabbedActivityTestBase {
         assertFalse(mDelegate.isInVR());
     }
 
+    private void testEnterExitVrModeImage(boolean supported) throws IOException {
+        int prevOrientation = getActivity().getRequestedOrientation();
+        getActivity().setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
+        getInstrumentation().waitForIdleSync();
+        mViewRenderer.renderAndCompare(
+                getActivity().getWindow().getDecorView().getRootView(),
+                "blank_page");
+
+        forceEnterVr();
+        getInstrumentation().waitForIdleSync();
+        // Currently, screenshots only show the static UI overlay, not the
+        // actual content. Thus, 1:1 pixel checking is reliable until a
+        // way to take screenshots of VR content is added, in which case
+        // % similarity or some other method will need to be used. We're
+        // assuming that if the UI overlay is visible, then the device has
+        // successfully entered VR mode.
+        if (supported) {
+            mViewRenderer.renderAndCompare(
+                    getActivity().getWindow().getDecorView().getRootView(),
+                    "vr_entered");
+        } else {
+            mViewRenderer.renderAndCompare(
+                    getActivity().getWindow().getDecorView().getRootView(),
+                    "blank_page");
+        }
+
+        forceExitVr();
+        getActivity().setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
+        getInstrumentation().waitForIdleSync();
+        mViewRenderer.renderAndCompare(
+                getActivity().getWindow().getDecorView().getRootView(),
+                "blank_page");
+
+        getActivity().setRequestedOrientation(prevOrientation);
+    }
+
     /**
      * Verifies that browser successfully enters and exits VR mode when told to
      * on Daydream-ready devices. Requires that the phone is unlocked.
@@ -80,4 +124,27 @@ public class VrShellTest extends ChromeTabbedActivityTestBase {
     public void testEnterExitVrModeUnsupported() {
         testEnterExitVrMode(false);
     }
+
+    /**
+     * Verifies that browser successfully enters and exits VR mode when told to
+     * on Daydream-ready devices via a screendiffing check.
+     * Requires that the phone is unlocked.
+     */
+    @Restriction(RESTRICTION_TYPE_DAYDREAM)
+    @Feature("RenderTest")
+    @MediumTest
+    public void testEnterExitVrModeSupportedImage() throws IOException {
+        testEnterExitVrModeImage(true);
+    }
+
+    /**
+     * Verifies that browser does not enter VR mode on Non-Daydream-ready devices
+     * via a screendiffing check. Requires that the phone is unlocked.
+     */
+    @Restriction(RESTRICTION_TYPE_NON_DAYDREAM)
+    @Feature("RenderTest")
+    @MediumTest
+    public void testEnterExitVrModeUnsupportedImage() throws IOException {
+        testEnterExitVrModeImage(false);
+    }
 }