chromecast: Destroy WindowAndroid

WindowAndroid needs to be explicitly destroyed. Caught this while trying
to add LifetimeAssert to WindowAndroid to enforce this.

Bug: 1081250
Change-Id: I2e888b8875f856946abb83fb91fd32d60845304b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2212793Reviewed-by: Simeon Anfinrud <sanfin@chromium.org>
Commit-Queue: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#771212}

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastWebContentsScopes.java

@@ -102,7 +102,12 @@ class CastWebContentsScopes {
                     // WebContents can be destroyed by the app before CastWebContentsComponent
                     // unbinds, which is why we need this check.
                     webContents.onHide();
+
+                    if (webContents.getTopLevelNativeWindow() == window) {
+                        webContents.setTopLevelNativeWindow(null);
                     }
+                }
+                window.destroy();
             };
         };
     }

chromecast/browser/android/junit/src/org/chromium/chromecast/shell/CastWebContentsServiceTest.java

@@ -21,6 +21,7 @@ import android.content.IntentFilter;
 import android.net.Uri;
 import android.os.PatternMatcher;
 
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -92,6 +93,12 @@ public class CastWebContentsServiceTest {
         mShadowService = Shadows.shadowOf(mService);
     }
 
+    @After
+    public void tearDown() {
+        mServiceLifecycle.unbind();
+        mServiceLifecycle.destroy();
+    }
+
     @Test
     public void testForegroundedAfterBind() {
         mServiceLifecycle.bind();