Add missing const on CSSTokenizerInputStream methods.

third_party/WebKit/Source/core/css/parser/CSSTokenizerInputStream.cpp

Index: third_party/WebKit/Source/core/css/parser/CSSTokenizerInputStream.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSTokenizerInputStream.cpp b/third_party/WebKit/Source/core/css/parser/CSSTokenizerInputStream.cpp
index e95cbd74aff3ea6b0cc7942ba724bf5c3450f017..b01628426d8fad8656057df485c1120b1d203cd5 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSTokenizerInputStream.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSTokenizerInputStream.cpp
@@ -17,7 +17,7 @@ CSSTokenizerInputStream::CSSTokenizerInputStream(String input)
 {
 }
 
-UChar CSSTokenizerInputStream::peek(unsigned lookaheadOffset)
+UChar CSSTokenizerInputStream::peek(unsigned lookaheadOffset) const
 {
     if ((m_offset + lookaheadOffset) >= m_stringLength)
         return kEndOfFileMarker;
@@ -25,12 +25,6 @@ UChar CSSTokenizerInputStream::peek(unsigned lookaheadOffset)
     return result ? result : 0xFFFD;
 }
 
-void CSSTokenizerInputStream::pushBack(UChar cc)
-{
-    --m_offset;
-    ASSERT(nextInputChar() == cc);
-}
-
 void CSSTokenizerInputStream::advanceUntilNonWhitespace()
 {
     // Using HTML space here rather than CSS space since we don't do preprocessing
@@ -45,9 +39,9 @@ void CSSTokenizerInputStream::advanceUntilNonWhitespace()
     }
 }
 
-double CSSTokenizerInputStream::getDouble(unsigned start, unsigned end)
+double CSSTokenizerInputStream::getDouble(unsigned start, unsigned end) const
 {
-    ASSERT(start <= end && ((m_offset + end) <= m_stringLength));
+    DCHECK(start <= end && ((m_offset + end) <= m_stringLength));
     bool isResultOK = false;
     double result = 0.0;
     if (start < end) {
@@ -62,7 +56,7 @@ double CSSTokenizerInputStream::getDouble(unsigned start, unsigned end)
 
 StringView CSSTokenizerInputStream::rangeAt(unsigned start, unsigned length) const
 {
-    ASSERT(start + length <= m_stringLength);
+    DCHECK(start + length <= m_stringLength);
     return StringView(m_string.get(), start, length);
 }