import org.chromium.base.BaseChromiumApplication; //导入依赖的package包/类
@Override
public void onActivityStateChange(Activity activity, int newState) {
    if (newState == ActivityState.STOPPED) {
        // Exit fullscreen in onStop to ensure the system UI flags are set correctly when
        // showing again (on JB MR2+ builds, the omnibox would be covered by the
        // notification bar when this was done in onStart()).
        setPersistentFullscreenMode(false);
    } else if (newState == ActivityState.STARTED) {
        ThreadUtils.postOnUiThreadDelayed(new Runnable() {
            @Override
            public void run() {
                mBrowserVisibilityDelegate.showControlsTransient();
            }
        }, ACTIVITY_RETURN_SHOW_REQUEST_DELAY_MS);
    } else if (newState == ActivityState.DESTROYED) {
        ApplicationStatus.unregisterActivityStateListener(this);
        ((BaseChromiumApplication) mWindow.getContext().getApplicationContext())
                .unregisterWindowFocusChangedListener(this);

        mTabModelObserver.destroy();
    }
}
 

import org.chromium.base.BaseChromiumApplication; //导入依赖的package包/类
@Override
public void onActivityStateChange(Activity activity, int newState) {
    if (newState == ActivityState.STOPPED) {
        // Exit fullscreen in onStop to ensure the system UI flags are set correctly when
        // showing again (on JB MR2+ builds, the omnibox would be covered by the
        // notification bar when this was done in onStart()).
        setPersistentFullscreenMode(false);
    } else if (newState == ActivityState.STARTED) {
        // Force the controls to be shown until we get an update from a Tab.  This is a
        // workaround for when the renderer is killed but the Tab is not notified.
        mActivityShowToken = showControlsPersistentAndClearOldToken(mActivityShowToken);
    } else if (newState == ActivityState.DESTROYED) {
        ApplicationStatus.unregisterActivityStateListener(this);
        ((BaseChromiumApplication) mWindow.getContext().getApplicationContext())
                .unregisterWindowFocusChangedListener(this);
    }
}
 

import org.chromium.base.BaseChromiumApplication; //导入依赖的package包/类
@Override
public void onActivityStateChange(Activity activity, int newState) {
    if (newState == ActivityState.STOPPED && mExitFullscreenOnStop) {
        // Exit fullscreen in onStop to ensure the system UI flags are set correctly when
        // showing again (on JB MR2+ builds, the omnibox would be covered by the
        // notification bar when this was done in onStart()).
        setPersistentFullscreenMode(false);
    } else if (newState == ActivityState.STARTED) {
        ThreadUtils.postOnUiThreadDelayed(new Runnable() {
            @Override
            public void run() {
                mBrowserVisibilityDelegate.showControlsTransient();
            }
        }, ACTIVITY_RETURN_SHOW_REQUEST_DELAY_MS);
    } else if (newState == ActivityState.DESTROYED) {
        ApplicationStatus.unregisterActivityStateListener(this);
        ((BaseChromiumApplication) mWindow.getContext().getApplicationContext())
                .unregisterWindowFocusChangedListener(this);

        mTabModelObserver.destroy();
    }
}