Minor Gradient cleanup.

There is no need to manipulate the sorted state externally, we can
efficiently detect sorted color stops on the fly. This may also avoid
a sort pass in some cases.

R=pdr@chromium.org,schenney@chromium.org,rob.buis@samsung.com

Review URL: https://codereview.chromium.org/206493002

git-svn-id: svn://svn.chromium.org/blink/trunk@169660 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/css/CSSGradientValue.cpp

@@ -157,8 +157,6 @@ void CSSGradientValue::addStops(Gradient* gradient, const CSSToLengthConversionD
             gradient->addColorStop(offset, stop.m_resolvedColor);
         }
 
-        // The back end already sorted the stops.
-        gradient->setStopsSorted(true);
         return;
     }
 
@@ -389,8 +387,6 @@ void CSSGradientValue::addStops(Gradient* gradient, const CSSToLengthConversionD
 
     for (unsigned i = 0; i < numStops; i++)
         gradient->addColorStop(stops[i].offset, stops[i].color);
-
-    gradient->setStopsSorted(true);
 }
 
 static float positionFromValue(CSSPrimitiveValue* value, const CSSToLengthConversionData& conversionData, const IntSize& size, bool isHorizontal)

third_party/WebKit/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)

third_party/WebKit/Source/platform/graphics/Gradient.h

@@ -65,7 +65,7 @@ public:
         ColorStop(float s, const Color& c) : stop(s), color(c) { }
     };
     void addColorStop(const ColorStop&);
-    void addColorStop(float, const Color&);
+    void addColorStop(float value, const Color& color) { addColorStop(ColorStop(value, color)); }
 
     bool hasAlpha() const;
     bool shaderChanged() const { return !m_gradient; }
@@ -115,8 +115,6 @@ public:
 
     SkShader* shader();
 
-    void setStopsSorted(bool s) { m_stopsSorted = s; }
-
     void setDrawsInPMColorSpace(bool drawInPMColorSpace);
 
     void setSpreadMethod(GradientSpreadMethod);