Teach WebString about 8 bit strings

public/platform/WebString.h

 /*
  * Copyright (C) 2009 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 20 matching lines @@
 #ifndef WebString_h
 #define WebString_h
 
 #include "WebCommon.h"
 
 #if WEBKIT_IMPLEMENTATION
 #include <wtf/Forward.h>
 #else
 #include <base/nullable_string16.h>
 #include <base/string16.h>
+#include <base/strings/latin1_string_conversions.h>
 #endif
 
 namespace WebKit {
 
 class WebCString;
 class WebStringPrivate;
 
 // A UTF-16 string container.  It is inexpensive to copy a WebString
 // object.
 //
@@ skipping 18 matching lines @@
         return *this;
     }
 
     WEBKIT_EXPORT void reset();
     WEBKIT_EXPORT void assign(const WebString&);
     WEBKIT_EXPORT void assign(const WebUChar* data, size_t len);
 
     WEBKIT_EXPORT bool equals(const WebString& s) const;
 
     WEBKIT_EXPORT size_t length() const;
+    // Deprecated: This function will be removed once all its callers are gone.
     WEBKIT_EXPORT const WebUChar* data() const;
 
     // Caller must check bounds.
     WEBKIT_EXPORT WebUChar at(unsigned) const;
 
     bool isEmpty() const { return !length(); }
     bool isNull() const { return !m_private; }
 
     WEBKIT_EXPORT WebCString utf8() const;
 
@@ skipping 28 matching lines @@
     }
 
     WebString& operator=(const string16& s)
     {
         assign(s.data(), s.length());
         return *this;
     }
 
     operator string16() const
     {
-        size_t len = length();
-        return len ? string16(data(), len) : string16();
+        return base::Latin1OrUTF16ToUTF16(length(), data8(), data16());
     }
 
     WebString(const NullableString16& s) : m_private(0)
     {
         if (s.is_null())
             reset();
         else
             assign(s.string().data(), s.string().length());
     }
 
     WebString& operator=(const NullableString16& s)
     {
         if (s.is_null())
             reset();
         else
             assign(s.string().data(), s.string().length());
         return *this;
     }
 
     operator NullableString16() const
     {
-        if (!m_private)
-            return NullableString16(string16(), true);
-        size_t len = length();
-        return NullableString16(len ? string16(data(), len) : string16(), false);
+        return NullableString16(operator string16(), !m_private);
     }
 
     template <class UTF8String>
     static WebString fromUTF8(const UTF8String& s)
     {
         return fromUTF8(s.data(), s.length());
     }
 #endif
 
 private:
+    WEBKIT_EXPORT bool is8Bit() const;
+    WEBKIT_EXPORT const WebLChar* data8() const;
+    WEBKIT_EXPORT const WebUChar* data16() const;
+
     void assign(WebStringPrivate*);
 
     WebStringPrivate* m_private;
 };
 
 inline bool operator==(const WebString& a, const WebString& b)
 {
     return a.equals(b);
 }
 
 inline bool operator!=(const WebString& a, const WebString& b)
 {
     return !(a == b);
 }
 
 } // namespace WebKit
 
 #endif