Add test for validating the proper size when we exit WebVR to VR browsing.

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

Index: chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/VrShellNavigationTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/VrShellNavigationTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/VrShellNavigationTest.java
index d6e9154e8d2951775b31ae724934649c5a77364f..69cabcc4b8ba67489950eebe48ad9f4fe0ef2e61 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/VrShellNavigationTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/VrShellNavigationTest.java
@@ -27,6 +27,7 @@ import org.chromium.chrome.test.util.ChromeTabUtils;
 import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content.browser.test.util.DOMUtils;
 import org.chromium.content_public.browser.WebContents;
+import org.chromium.ui.display.DisplayAndroid;
 
 import java.util.concurrent.TimeoutException;
 
@@ -260,4 +261,36 @@ public class VrShellNavigationTest {
         assertState(mVrTestRule.getFirstTabWebContents(), Page.PAGE_WEBVR,
                 PresentationMode.NON_PRESENTING, FullscreenMode.NON_FULLSCREENED);
     }
+
+    /**
+     * Tests exit presentation transition from WebVR to VrShell
+     */
+    @Test
+    @CommandLineFlags.Add("enable-webvr")
+    @MediumTest
+    public void testExitPresentationWebVrToVrShell()

[tiborg, 2017/06/02 15:36:51]

This test should probably not be here. VrShellTest would be better. Or a new
test where we test presentation <-> non-presentation, fullscreen <->
non-fullscreen kind of tests.

+            throws IllegalArgumentException, InterruptedException, TimeoutException {
+        mVrTestRule.loadUrlAndAwaitInitialization(TEST_PAGE_WEBVR_URL, PAGE_LOAD_TIMEOUT_S);
+        enterPresentationOrFail(mVrTestRule.getFirstTabCvc());
+
+        // Validate our size is what we expect.
+        DisplayAndroid primaryDisplay =
+                DisplayAndroid.getNonMultiDisplay(mVrTestRule.getActivity());
+        float expectedWidth = primaryDisplay.getDisplayWidth();
+        float expectedHeight = primaryDisplay.getDisplayHeight();
+        Assert.assertTrue(mVrTestRule.pollJavaScriptBoolean(
+                "screen.width == " + expectedWidth + " && screen.height == " + expectedHeight,
+                POLL_TIMEOUT_LONG_MS, mVrTestRule.getFirstTabWebContents()));
+
+        // Exit presentation through JavaScript.
+        mVrTestRule.runJavaScriptOrFail("vrDisplay.exitPresent();", POLL_TIMEOUT_SHORT_MS,
+                mVrTestRule.getFirstTabWebContents());
+
+        // Validate our size is what we expect.
+        expectedWidth = VrShellImpl.DEFAULT_CONTENT_WIDTH;
+        expectedHeight = VrShellImpl.DEFAULT_CONTENT_HEIGHT;
+        Assert.assertTrue(mVrTestRule.pollJavaScriptBoolean(
+                "screen.width == " + expectedWidth + " && screen.height == " + expectedHeight,
+                POLL_TIMEOUT_LONG_MS, mVrTestRule.getFirstTabWebContents()));
+    }
 }