Minor Gradient cleanup.

Source/platform/graphics/Gradient.cpp

Index: Source/platform/graphics/Gradient.cpp
diff --git a/Source/platform/graphics/Gradient.cpp b/Source/platform/graphics/Gradient.cpp
index 0741e855616bb1f6e756c5c9ee32b8dd92351708..9c10bed4648e69caae3ca5535ff33b1bb2396249 100644
--- a/Source/platform/graphics/Gradient.cpp
+++ b/Source/platform/graphics/Gradient.cpp
@@ -68,27 +68,23 @@ Gradient::~Gradient()
 {
 }
 
-void Gradient::addColorStop(float value, const Color& color)
+static inline bool compareStops(const Gradient::ColorStop& a, const Gradient::ColorStop& b)
 {
-    m_stops.append(ColorStop(value, color));
-
-    m_stopsSorted = false;
-    m_gradient.clear();
+    return a.stop < b.stop;
 }
 
 void Gradient::addColorStop(const Gradient::ColorStop& stop)
 {
-    m_stops.append(stop);
+    if (m_stops.isEmpty()) {
+        m_stopsSorted = true;
+    } else {
+        m_stopsSorted = m_stopsSorted && compareStops(m_stops.last(), stop);
+    }
 
-    m_stopsSorted = false;
+    m_stops.append(stop);
     m_gradient.clear();
 }
 
-static inline bool compareStops(const Gradient::ColorStop& a, const Gradient::ColorStop& b)
-{
-    return a.stop < b.stop;
-}
-
 void Gradient::sortStopsIfNecessary()
 {
     if (m_stopsSorted)