Add setStartValue to RNA

 Bug: 15198607
 Should be good-enough for Ripples to use for pseudo-chaining
 support.

Change-Id: Ia8666928ccb69ae401cb583751632a52bd928b63
diff --git a/libs/hwui/Animator.cpp b/libs/hwui/Animator.cpp
index b80f7e9..eff3011 100644
--- a/libs/hwui/Animator.cpp
+++ b/libs/hwui/Animator.cpp
@@ -63,7 +63,6 @@
 void BaseRenderNodeAnimator::setupStartValueIfNecessary(RenderNode* target, TreeInfo& info) {
     if (mPlayState == NEEDS_START) {
         setStartValue(getValue(target));
-        mPlayState = PENDING;
     }
 }
 
@@ -154,7 +153,8 @@
 }
 
 void RenderPropertyAnimator::onAttached(RenderNode* target) {
-    if (target->isPropertyFieldDirty(mPropertyAccess->dirtyMask)) {
+    if (mPlayState == NEEDS_START
+            && target->isPropertyFieldDirty(mPropertyAccess->dirtyMask)) {
         setStartValue((target->stagingProperties().*mPropertyAccess->getter)());
     }
     (target->mutateStagingProperties().*mPropertyAccess->setter)(finalValue());