Reduce ArImmersiveOverlay's dependencies on chrome

Bug: 843374
Change-Id: Ib21288785cf151bd19a6590c288cd1abb1cd3054
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2462348
Commit-Queue: Piotr Bialecki <bialpio@chromium.org>
Reviewed-by: Klaus Weidner <klausw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815400}

chrome/android/java/src/org/chromium/chrome/browser/vr/ArImmersiveOverlay.java

@@ -26,11 +26,10 @@ import org.chromium.base.Log;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.app.ChromeActivity;
 import org.chromium.chrome.browser.compositor.CompositorView;
-import org.chromium.chrome.browser.fullscreen.FullscreenManager;
-import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.content_public.browser.ScreenOrientationDelegate;
 import org.chromium.content_public.browser.ScreenOrientationProvider;
 import org.chromium.content_public.browser.WebContents;
+import org.chromium.content_public.browser.WebContentsObserver;
 import org.chromium.ui.display.DisplayAndroidManager;
 import org.chromium.ui.widget.Toast;
 
@@ -51,6 +50,7 @@ public class ArImmersiveOverlay
     private Integer mRestoreOrientation;
     private boolean mCleanupInProgress;
     private SurfaceUiWrapper mSurfaceUi;
+    private WebContents mWebContents;
 
     // Set containing all currently touching pointers.
     private HashMap<Integer, PointerData> mPointerIdToData;
@@ -61,6 +61,8 @@ public class ArImmersiveOverlay
             @NonNull WebContents webContents, @NonNull ArCoreJavaUtils caller, boolean useOverlay) {
         if (DEBUG_LOGS) Log.i(TAG, "constructor");
         mArCoreJavaUtils = caller;
+
+        mWebContents = webContents;
         mActivity = ChromeActivity.fromWebContents(webContents);
 
         mPointerIdToData = new HashMap<Integer, PointerData>();
@@ -162,7 +164,7 @@ public class ArImmersiveOverlay
     private class SurfaceUiCompositor implements SurfaceUiWrapper {
         private SurfaceView mSurfaceView;
         private CompositorView mCompositorView;
-        private FullscreenManager.Observer mFullscreenListener;
+        private WebContentsObserver mWebContentsObserver;
 
         public SurfaceUiCompositor() {
             mSurfaceView = new SurfaceView(mActivity);
@@ -187,16 +189,23 @@ public class ArImmersiveOverlay
             if (DEBUG_LOGS) Log.i(TAG, "calling mCompositorView.setOverlayImmersiveArMode(true)");
             mCompositorView.setOverlayImmersiveArMode(true);
 
-            mFullscreenListener = new FullscreenManager.Observer() {
+            mWebContentsObserver = new WebContentsObserver() {
                 @Override
-                public void onExitFullscreen(Tab tab) {
-                    if (DEBUG_LOGS) Log.i(TAG, "onExitFullscreenMode");
-                    cleanupAndExit();
+                public void hasEffectivelyFullscreenVideoChange(boolean isFullscreen) {
+                    if (DEBUG_LOGS) {
+                        Log.i(TAG,
+                                "hasEffectivelyFullscreenVideoChange(), isFullscreen="
+                                        + isFullscreen);
+                    }
+
+                    if (!isFullscreen) {
+                        cleanupAndExit();
+                    }
                 }
             };
 
             // Watch for fullscreen exit triggered from JS, this needs to end the session.
-            mActivity.getFullscreenManager().addObserver(mFullscreenListener);
+            mWebContents.addObserver(mWebContentsObserver);
         }
 
         @Override // SurfaceUiWrapper
@@ -210,7 +219,7 @@ public class ArImmersiveOverlay
 
         @Override // SurfaceUiWrapper
         public void destroy() {
-            mActivity.getFullscreenManager().removeObserver(mFullscreenListener);
+            mWebContents.removeObserver(mWebContentsObserver);
             View content = mActivity.getWindow().findViewById(android.R.id.content);
             ViewGroup group = (ViewGroup) content.getParent();
             group.removeView(mSurfaceView);
@@ -502,8 +511,8 @@ public class ArImmersiveOverlay
         // The JS app may have put an element into fullscreen mode during the immersive session,
         // even if this wasn't visible to the user. Ensure that we fully exit out of any active
         // fullscreen state on session end to avoid being left in a confusing state.
-        if (mActivity.getActivityTab() != null && !mActivity.isActivityFinishingOrDestroyed()) {
-            mActivity.getFullscreenManager().onExitFullscreen(mActivity.getActivityTab());
+        if (!mWebContents.isDestroyed()) {
+            mWebContents.exitFullscreen();
         }
 
         // Restore orientation.