Fix double comparisons for Media Queries

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

 /*
  * CSS Media Query Evaluator
  *
  * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 155 matching lines @@
     case MinPrefix:
         return a >= b;
     case MaxPrefix:
         return a <= b;
     case NoPrefix:
         return a == b;
     }
     return false;
 }
 
+bool compareDoubleValue(double a, double b, MediaFeaturePrefix op)
+{
+    const double precision = std::numeric_limits<double>::epsilon();
+    switch (op) {
+    case MinPrefix:
+        return a >= (b - precision);
+    case MaxPrefix:
+        return a <= (b + precision);
+    case NoPrefix:
+        return std::abs(a - b) <= precision;
+    }
+    return false;
+}
+
 static bool compareAspectRatioValue(const MediaQueryExpValue& value, int width, int height, MediaFeaturePrefix op)
 {
     if (value.isRatio)
         return compareValue(width * static_cast<int>(value.denominator), height * static_cast<int>(value.numerator), op);
 
     return false;
 }
 
 static bool numberValue(const MediaQueryExpValue& value, float& result)
 {
@@ skipping 181 matching lines @@
     }
 
     if (CSSPrimitiveValue::isLength(value.unit))
         return mediaValues.computeLength(value.value, value.unit, result);
     return false;
 }
 
 static bool computeLengthAndCompare(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues, double compareToValue)
 {
     double length;
-    return computeLength(value, mediaValues, length) && compareValue(compareToValue, length, op);
+    return computeLength(value, mediaValues, length) && compareDoubleValue(compareToValue, length, op);
 }
 
 static bool deviceHeightMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
 {
     if (value.isValid())
         return computeLengthAndCompare(value, op, mediaValues, mediaValues.deviceHeight());
 
     // ({,min-,max-}device-height)
     // assume if we have a device, assume non-zero
     return true;
@@ skipping 277 matching lines @@
     // Call the media feature evaluation function. Assume no prefix and let
     // trampoline functions override the prefix if prefix is used.
     EvalFunc func = gFunctionMap->get(expr->mediaFeature().impl());
     if (func)
         return func(expr->expValue(), NoPrefix, *m_mediaValues);
 
     return false;
 }
 
 } // namespace blink