wtf: Implement StringView specialization of string concatenation.

third_party/WebKit/Source/wtf/text/StringOperators.h

Index: third_party/WebKit/Source/wtf/text/StringOperators.h
diff --git a/third_party/WebKit/Source/wtf/text/StringOperators.h b/third_party/WebKit/Source/wtf/text/StringOperators.h
index 9100cdaad788a75289554b3585206854c3a3b70e..8b4eac313530b3019cb9df1f911a52423e09074b 100644
--- a/third_party/WebKit/Source/wtf/text/StringOperators.h
+++ b/third_party/WebKit/Source/wtf/text/StringOperators.h
@@ -134,6 +134,11 @@ inline StringAppend<const char*, AtomicString> operator+(const char* string1, co
     return StringAppend<const char*, AtomicString>(string1, string2);
 }
 
+inline StringAppend<const char*, StringView> operator+(const char* string1, const StringView& string2)
+{
+    return StringAppend<const char*, StringView>(string1, string2);
+}
+
 template<typename U, typename V>
 inline StringAppend<const char*, StringAppend<U, V>> operator+(const char* string1, const StringAppend<U, V>& string2)
 {
@@ -150,6 +155,11 @@ inline StringAppend<const UChar*, AtomicString> operator+(const UChar* string1,
     return StringAppend<const UChar*, AtomicString>(string1, string2);
 }
 
+inline StringAppend<const UChar*, StringView> operator+(const UChar* string1, const StringView& string2)
+{
+    return StringAppend<const UChar*, StringView>(string1, string2);
+}
+
 template<typename U, typename V>
 inline StringAppend<const UChar*, StringAppend<U, V>> operator+(const UChar* string1, const StringAppend<U, V>& string2)
 {
@@ -162,6 +172,18 @@ StringAppend<String, T> operator+(const String& string1, T string2)
     return StringAppend<String, T>(string1, string2);
 }
 
+template<typename T>
+StringAppend<AtomicString, T> operator+(const AtomicString& string1, T string2)
+{
+    return StringAppend<AtomicString, T>(string1, string2);
+}
+
+template<typename T>
+StringAppend<StringView, T> operator+(const StringView& string1, T string2)
+{
+    return StringAppend<StringView, T>(string1, string2);
+}
+
 template<typename U, typename V, typename W>
 StringAppend<StringAppend<U, V>, W> operator+(const StringAppend<U, V>& string1, W string2)
 {