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

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

Index: third_party/WebKit/Source/wtf/text/StringBuilder.h
diff --git a/third_party/WebKit/Source/wtf/text/StringBuilder.h b/third_party/WebKit/Source/wtf/text/StringBuilder.h
index 73cc2655e83cf11ef4f42de10b749a4c8ea74ab4..0261743fa17d196a3a66c761b58e732c871ec51d 100644
--- a/third_party/WebKit/Source/wtf/text/StringBuilder.h
+++ b/third_party/WebKit/Source/wtf/text/StringBuilder.h
@@ -50,26 +50,6 @@ public:
 
     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)
@@ -89,7 +69,9 @@ public:
             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;
@@ -115,12 +97,6 @@ public:
             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()) {