Enable float source size

Source/core/css/parser/SizesAttributeParser.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SizesAttributeParser_h
 #define SizesAttributeParser_h
 
 #include "core/css/MediaValues.h"
 #include "core/css/parser/MediaQueryBlockWatcher.h"
 #include "core/css/parser/MediaQueryParser.h"
 #include "platform/heap/Handle.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class SizesAttributeParser {
     STACK_ALLOCATED();
 public:
     SizesAttributeParser(PassRefPtr<MediaValues>, const String&);
 
     bool viewportDependant() const { return m_viewportDependant; }
-    unsigned length();
+    float length();
 
 private:
     bool parse(Vector<MediaQueryToken>& tokens);
     bool parseMediaConditionAndLength(MediaQueryTokenIterator startToken, MediaQueryTokenIterator endToken);
-    unsigned effectiveSize();
-    bool calculateLengthInPixels(MediaQueryTokenIterator startToken, MediaQueryTokenIterator endToken, unsigned& result);
+    float effectiveSize();
+    bool calculateLengthInPixels(MediaQueryTokenIterator startToken, MediaQueryTokenIterator endToken, float& result);
     bool mediaConditionMatches(PassRefPtrWillBeRawPtr<MediaQuerySet> mediaCondition);
     unsigned effectiveSizeDefaultValue();
 
     RefPtrWillBeMember<MediaQuerySet> m_mediaCondition;
     RefPtr<MediaValues> m_mediaValues;
-    unsigned m_length;
+    float m_length;
     bool m_lengthWasSet;
     bool m_viewportDependant;
     Vector<MediaQueryToken> m_tokens;
     bool m_isValid;
     MediaQueryBlockWatcher m_blockWatcher;
 };
 
 } // namespace
 
 #endif