Avoid useless initialization in ScrollAnimatorNone::PerAxisData::animateScroll()

Source/platform/scroll/ScrollAnimatorNone.cpp

Index: Source/platform/scroll/ScrollAnimatorNone.cpp
diff --git a/Source/platform/scroll/ScrollAnimatorNone.cpp b/Source/platform/scroll/ScrollAnimatorNone.cpp
index 4a24201241b5a35b37f3c3de5060472d319feafb..cf21a24f99de6cb00571e993f1a37ad676c0c5a9 100644
--- a/Source/platform/scroll/ScrollAnimatorNone.cpp
+++ b/Source/platform/scroll/ScrollAnimatorNone.cpp
@@ -334,18 +334,18 @@ bool ScrollAnimatorNone::PerAxisData::animateScroll(double currentTime)
     m_lastAnimationTime = currentTime;
 
     double deltaTime = currentTime - m_startTime;
-    double newPosition = *m_currentPosition;
 
     if (deltaTime > m_animationTime) {
         *m_currentPosition = m_desiredPosition;
         reset();
         return false;
     }
-    if (deltaTime < m_attackTime)
+    double newPosition;

[abarth-chromium, 2014/04/20 14:10:05]

Can we initialize it to zero?  We generally like to initialize scalars.

[Inactive, 2014/04/20 15:00:56]

Counter proposal: I moved the initialization to a new inline function and
newPosition is now initialized with the the result of this new function. This
way we avoid the useless assignment, *and* the scalar is initialized. PTAL.

+    if (deltaTime < m_attackTime) {
         newPosition = attackCurve(m_attackCurve, deltaTime, m_attackTime, m_startPosition, m_attackPosition);
-    else if (deltaTime < (m_animationTime - m_releaseTime))
+    } else if (deltaTime < (m_animationTime - m_releaseTime)) {
         newPosition = m_attackPosition + (deltaTime - m_attackTime) * m_desiredVelocity;
-    else {
+    } else {
         // release is based on targeting the exact final position.
         double releaseDeltaT = deltaTime - (m_animationTime - m_releaseTime);
         newPosition = releaseCurve(m_releaseCurve, releaseDeltaT, m_releaseTime, m_releasePosition, m_desiredPosition);