GitLab

This CL:
- Prevents HomeCardGestureManager from calling OnGestureProgressed() with
  |from_state| == |to_state|
  - This fixes the minimized home card's opacity being incorrectly set when
    dragging down from the minimized state
- Removes unnecessary |HomeCardGestureManager::last_state_|

BUG=409666
TEST=HomeCardGestureManagerTest.*

Review URL: https://codereview.chromium.org/529813002

Cr-Commit-Position: refs/heads/master@{#293232}