Expand WTF::StringView's API to be more like StringPiece.

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

 /*
  * Copyright (C) 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 32 matching lines @@
         , m_length(0)
         , m_is8Bit(true)
     {
     }
 
     void append(const UChar*, unsigned);
     void append(const LChar*, unsigned);
 
     ALWAYS_INLINE void append(const char* characters, unsigned length) { append(reinterpret_cast<const LChar*>(characters), length); }
 
-    void append(const String& string)
-    {
-        if (!string.length())
-            return;
-
-        // If we're appending to an empty string, and there is not a buffer (reserveCapacity has not been called)
-        // then just retain the string.
-        if (!m_length && !m_buffer) {

[esprehn, 2016/05/26 20:59:08]

I did actually remove this optimization, but I audited the code and it doesn't
seem like this ever gets used. Plus doing another append() would require a
realloc anyway, and almost all of the usage of this method are doing multiple
appends, so doing an initial alloc with some extra space is probably worth it.

-            m_string = string;
-            m_length = string.length();
-            m_is8Bit = m_string.is8Bit();
-            return;
-        }
-
-        if (string.is8Bit())
-            append(string.characters8(), string.length());
-        else
-            append(string.characters16(), string.length());
-    }
-
     void append(const StringBuilder& other)
     {
         if (!other.m_length)
             return;
 
         // If we're appending to an empty string, and there is not a buffer (reserveCapacity has not been called)
         // then just retain the string.
         if (!m_length && !m_buffer && !other.m_string.isNull()) {
             m_string = other.m_string;
             m_length = other.m_length;
             return;
         }
 
         if (other.is8Bit())
             append(other.characters8(), other.m_length);
         else
             append(other.characters16(), other.m_length);
     }
 
-    void append(const String& string, unsigned offset, unsigned length)
+    // TODO(esprehn): This method is just duplicating what StringView itself
+    // does. Remove it and replace callers with append(StringView(string, offset, length)).
+    void append(const StringView& string, unsigned offset, unsigned length)
     {
         if (!string.length())
             return;
 
         unsigned extent = offset + length;
         if (extent < offset || extent > string.length())
             return;
 
         if (string.is8Bit())
             append(string.characters8() + offset, length);
         else
             append(string.characters16() + offset, length);
     }
 
     void append(const StringView& string)
     {
         if (!string.length())
             return;
 
         if (string.is8Bit())
             append(string.characters8(), string.length());
         else
             append(string.characters16(), string.length());
     }
 
-    void append(const char* characters)
-    {
-        if (characters)
-            append(characters, strlen(characters));
-    }
-
     void append(UChar c)
     {
         if (m_buffer && m_length < m_buffer->length() && m_string.isNull()) {
             if (!m_is8Bit) {
                 m_bufferCharacters16[m_length++] = c;
                 return;
             }
 
             if (!(c & ~0xff)) {
                 m_bufferCharacters8[m_length++] = static_cast<LChar>(c);
@@ skipping 260 matching lines @@
 inline bool operator==(const StringBuilder& a, const String& b) { return equal(a, b); }
 inline bool operator!=(const StringBuilder& a, const String& b) { return !equal(a, b); }
 inline bool operator==(const String& a, const StringBuilder& b) { return equal(b, a); }
 inline bool operator!=(const String& a, const StringBuilder& b) { return !equal(b, a); }
 
 } // namespace WTF
 
 using WTF::StringBuilder;
 
 #endif // StringBuilder_h