@NonNull
        public Builder setStartAnimations(
                @NonNull Context context, @AnimRes int enterResId, @AnimRes int exitResId) {
            mStartAnimationBundle = ActivityOptionsCompat.makeCustomAnimation(
                    context, enterResId, exitResId).toBundle();
            return this;
        }
Sets the start animations.

@param context Application context.
@param enterResId Resource ID of the "enter" animation for the browser.
@param exitResId Resource ID of the "exit" animation for the application.
customtabs/src/android/support/customtabs/CustomTabsIntent.java