Apply ValueAnimator scale factor immediately in WM.

Normally the ValueAnimator scale factor is applied the first
time a ViewRootImpl window session is created but that may
be too late for animators created by system services that
start early in the boot process.  So set the scale factor
immediately whenever the setting changes.

Also make ValueAnimator.getDurationScale() accessible (but @hide)
for custom animators that want to apply the same scale to
their animations.

Change-Id: I0f5a750ab5b014f63848445435d8dca86f2a7ada

Author: Jeff Brown

core/java/android/animation/ValueAnimator.java

@@ -231,6 +231,13 @@ public static void setDurationScale(float durationScale) {
         sDurationScale = durationScale;
     }
 
+    /**
+     * @hide
+     */
+    public static float getDurationScale() {
+        return sDurationScale;
+    }
+
     /**
      * Creates a new ValueAnimator object. This default constructor is primarily for
      * use internally; the factory methods which take parameters are more generally

services/java/com/android/server/wm/WindowManagerService.java

@@ -57,6 +57,7 @@
 import android.app.IActivityManager;
 import android.app.StatusBarManager;
 import android.app.admin.DevicePolicyManager;
+import android.animation.ValueAnimator;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
@@ -900,8 +901,8 @@ private WindowManagerService(Context context, PowerManagerService pm,
                 Settings.System.WINDOW_ANIMATION_SCALE, mWindowAnimationScale);
         mTransitionAnimationScale = Settings.System.getFloat(context.getContentResolver(),
                 Settings.System.TRANSITION_ANIMATION_SCALE, mTransitionAnimationScale);
-        mAnimatorDurationScale = Settings.System.getFloat(context.getContentResolver(),
-                Settings.System.ANIMATOR_DURATION_SCALE, mTransitionAnimationScale);
+        setAnimatorDurationScale(Settings.System.getFloat(context.getContentResolver(),
+                Settings.System.ANIMATOR_DURATION_SCALE, mTransitionAnimationScale));
 
         // Track changes to DevicePolicyManager state so we can enable/disable keyguard.
         IntentFilter filter = new IntentFilter();
@@ -5160,14 +5161,19 @@ public void setAnimationScales(float[] scales) {
                 mTransitionAnimationScale = fixScale(scales[1]);
             }
             if (scales.length >= 3) {
-                mAnimatorDurationScale = fixScale(scales[2]);
+                setAnimatorDurationScale(fixScale(scales[2]));
             }
         }
 
         // Persist setting
         mH.obtainMessage(H.PERSIST_ANIMATION_SCALE).sendToTarget();
     }
 
+    private void setAnimatorDurationScale(float scale) {
+        mAnimatorDurationScale = scale;
+        ValueAnimator.setDurationScale(scale);
+    }
+
     public float getAnimationScale(int which) {
         switch (which) {
             case 0: return mWindowAnimationScale;