Fix three bugs in the equals() implementations for css gradients.

Source/core/css/CSSGradientValue.cpp

 /*
  * Copyright (C) 2008 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 705 matching lines @@
 
     if (m_repeating != other.m_repeating)
         return false;
 
     if (m_angle)
         return compareCSSValuePtr(m_angle, other.m_angle) && m_stops == other.m_stops;
 
     if (other.m_angle)
         return false;
 
-    bool equalXorY = false;
+    bool equalXandY = false;
     if (m_firstX && m_firstY)
-        equalXorY = compareCSSValuePtr(m_firstX, other.m_firstX) && compareCSSValuePtr(m_firstY, other.m_firstY);
+        equalXandY = compareCSSValuePtr(m_firstX, other.m_firstX) && compareCSSValuePtr(m_firstY, other.m_firstY);
     else if (m_firstX)
-        equalXorY =compareCSSValuePtr(m_firstX, other.m_firstX) && !other.m_firstY;
+        equalXandY = compareCSSValuePtr(m_firstX, other.m_firstX) && !other.m_firstY;
     else if (m_firstY)
-        equalXorY = compareCSSValuePtr(m_firstY, other.m_firstY) && !other.m_firstX;
+        equalXandY = compareCSSValuePtr(m_firstY, other.m_firstY) && !other.m_firstX;
     else
-        equalXorY = !other.m_firstX || !other.m_firstY;
+        equalXandY = !other.m_firstX && !other.m_firstY;
 
-    return equalXorY && m_stops == other.m_stops;
+    return equalXandY && m_stops == other.m_stops;
 }
 
 String CSSRadialGradientValue::customCSSText() const
 {
     StringBuilder result;
 
     if (m_gradientType == CSSDeprecatedRadialGradient) {
         result.appendLiteral("-webkit-gradient(radial, ");
         result.append(m_firstX->cssText());
         result.append(' ');
@@ skipping 383 matching lines @@
             && compareCSSValuePtr(m_firstY, other.m_firstY)
             && compareCSSValuePtr(m_secondX, other.m_secondX)
             && compareCSSValuePtr(m_secondY, other.m_secondY)
             && compareCSSValuePtr(m_firstRadius, other.m_firstRadius)
             && compareCSSValuePtr(m_secondRadius, other.m_secondRadius)
             && m_stops == other.m_stops;
 
     if (m_repeating != other.m_repeating)
         return false;
 
-    bool equalXorY = false;
+    bool equalXandY = false;
     if (m_firstX && m_firstY)
-        equalXorY = compareCSSValuePtr(m_firstX, other.m_firstX) && compareCSSValuePtr(m_firstY, other.m_firstY);
+        equalXandY = compareCSSValuePtr(m_firstX, other.m_firstX) && compareCSSValuePtr(m_firstY, other.m_firstY);
     else if (m_firstX)
-        equalXorY = compareCSSValuePtr(m_firstX, other.m_firstX) && !other.m_firstY;
+        equalXandY = compareCSSValuePtr(m_firstX, other.m_firstX) && !other.m_firstY;
     else if (m_firstY)
-        equalXorY = compareCSSValuePtr(m_firstY, other.m_firstY) && !other.m_firstX;
+        equalXandY = compareCSSValuePtr(m_firstY, other.m_firstY) && !other.m_firstX;
     else
-        equalXorY == !other.m_firstX || !other.m_firstY;
+        equalXandY = !other.m_firstX && !other.m_firstY;
 
-    if (!equalXorY)
+    if (!equalXandY)
         return false;
 
     bool equalShape = true;
     bool equalSizingBehavior = true;
     bool equalHorizontalAndVerticalSize = true;
 
     if (m_shape)
         equalShape = compareCSSValuePtr(m_shape, other.m_shape);
     else if (m_sizingBehavior)
         equalSizingBehavior = compareCSSValuePtr(m_sizingBehavior, other.m_sizingBehavior);
     else if (m_endHorizontalSize && m_endVerticalSize)
         equalHorizontalAndVerticalSize = compareCSSValuePtr(m_endHorizontalSize, other.m_endHorizontalSize) && compareCSSValuePtr(m_endVerticalSize, other.m_endVerticalSize);
     else {
         equalShape = !other.m_shape;
         equalSizingBehavior = !other.m_sizingBehavior;
         equalHorizontalAndVerticalSize = !other.m_endHorizontalSize && !other.m_endVerticalSize;
     }
     return equalShape && equalSizingBehavior && equalHorizontalAndVerticalSize && m_stops == other.m_stops;
 }
 
 } // namespace WebCore