Additional fixes for "back" with translucent windows.

Ensure background is mutated before changing its alpha.
Ensure resetViews is called when activity options is set.

Bug 16215650

Change-Id: I8482532777652a93b2c0d05c1b902516d281baf0

core/java/android/app/ActivityTransitionState.java

@@ -151,6 +151,7 @@ class ActivityTransitionState {
             mEnterActivityOptions = options;
             mIsEnterTriggered = false;
             if (mEnterActivityOptions.isReturning()) {
+                restoreExitedViews();
                 int result = mEnterActivityOptions.getResultCode();
                 if (result != 0) {
                     activity.onActivityReenter(result, mEnterActivityOptions.getResultData());

core/java/android/app/EnterTransitionCoordinator.java

@@ -466,6 +466,7 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
             Drawable background = getDecor().getBackground();
             if (background != null) {
                 background = background.mutate();
+                getWindow().setBackgroundDrawable(background);
                 mBackgroundAnimator = ObjectAnimator.ofInt(background, "alpha", 255);
                 mBackgroundAnimator.setDuration(getFadeDuration());
                 mBackgroundAnimator.addListener(new AnimatorListenerAdapter() {

core/java/android/app/ExitTransitionCoordinator.java

@@ -259,6 +259,8 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
             ViewGroup decor = getDecor();
             Drawable background;
             if (decor != null && (background = decor.getBackground()) != null) {
+                background = background.mutate();
+                getWindow().setBackgroundDrawable(background);
                 mBackgroundAnimator = ObjectAnimator.ofInt(background, "alpha", 0);
                 mBackgroundAnimator.addListener(new AnimatorListenerAdapter() {
                     @Override