Remove reliance on surface to update depth

- Also no longer resets depth on surface change, as depth is independent
  from blur.

This fixes the bug where depth is not accurately reflected.

Bug: 185680609
Bug: 185189176
Test: launch app and swipe home multiple times
      launch app and back gesture to home

Change-Id: I5e2f4ce08b8bf84b7356fbd080ae732875c5e04e
diff --git a/quickstep/src/com/android/launcher3/statehandlers/DepthController.java b/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
index 249ef3a..59d0afa 100644
--- a/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
+++ b/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
@@ -158,11 +158,7 @@
      * Sets the specified app target surface to apply the blur to.
      */
     public void setSurfaceToApp(RemoteAnimationTargetCompat target) {
-        if (target != null) {
-            setSurface(target.leash);
-        } else {
-            setActivityStarted(mLauncher.isStarted());
-        }
+        setSurface(target == null ? null : target.leash);
     }
 
     private void setSurface(SurfaceControlCompat surface) {
@@ -170,9 +166,6 @@
             mSurface = surface;
             if (surface != null) {
                 setDepth(mDepth);
-            } else {
-                // If there is no surface, then reset the ratio
-                setDepth(0f);
             }
         }
     }
@@ -192,8 +185,7 @@
     @Override
     public void setStateWithAnimation(LauncherState toState, StateAnimationConfig config,
             PendingAnimation animation) {
-        if (mSurface == null
-                || config.hasAnimationFlag(SKIP_DEPTH_CONTROLLER)
+        if (config.hasAnimationFlag(SKIP_DEPTH_CONTROLLER)
                 || mIgnoreStateChangesDuringMultiWindowAnimation) {
             return;
         }