Replace CSSParserString with StringView.

third_party/WebKit/Source/wtf/text/StringView.cpp

Index: third_party/WebKit/Source/wtf/text/StringView.cpp
diff --git a/third_party/WebKit/Source/wtf/text/StringView.cpp b/third_party/WebKit/Source/wtf/text/StringView.cpp
index fea433c4225f1e65ed72158902949d58be54a75f..4df160186f49e6d51a750dd020854b5e838443f9 100644
--- a/third_party/WebKit/Source/wtf/text/StringView.cpp
+++ b/third_party/WebKit/Source/wtf/text/StringView.cpp
@@ -51,4 +51,20 @@ bool equalStringView(const StringView& a, const StringView& b)
     return equal(a.characters16(), b.characters16(), a.length());
 }
 
+bool equalIgnoringASCIICase(StringView a, StringView b)
+{
+    if (a.length() != b.length())
+        return false;
+    if (a.isEmpty() || b.isEmpty())

[Timothy Loh, 2016/06/01 05:51:32]

How about:

if (a.isEmpty())
    return true;

Or just remove the branch, I can't imagine this early-out being particularly
common.

[esprehn, 2016/06/01 06:19:04]

I see that the method in StringImpl.h does accept strings, the libc things like
memcmp don't even if the length is 0.

I was actually trying to match the semantics of String and StringImpl. I see now
that they make it so null strings are only ever equal to other null strings. I
changed this to do that too and added tests. I want to make StringView a drop in
replacement wherever possible without having subtle differences.

+        return a.isEmpty() == b.isEmpty();
+    if (a.is8Bit()) {
+        if (b.is8Bit())
+            return equalIgnoringASCIICase(a.characters8(), b.characters8(), a.length());
+        return equalIgnoringASCIICase(a.characters8(), b.characters16(), a.length());
+    }
+    if (b.is8Bit())
+        return equalIgnoringASCIICase(a.characters16(), b.characters8(), a.length());
+    return equalIgnoringASCIICase(a.characters16(), b.characters16(), a.length());
+}
+
 } // namespace WTF