Move btoa() / atob() implementation out of DOMWindow

Source/core/page/DOMWindow.cpp

Index: Source/core/page/DOMWindow.cpp
diff --git a/Source/core/page/DOMWindow.cpp b/Source/core/page/DOMWindow.cpp
index 830dc7edd04931cc6887740f27188cbbfbf5da95..6cde87e54c40971be7046abc00623c7a1cda25d4 100644
--- a/Source/core/page/DOMWindow.cpp
+++ b/Source/core/page/DOMWindow.cpp
@@ -29,7 +29,6 @@
 
 #include "wtf/MainThread.h"
 #include "wtf/MathExtras.h"
-#include "wtf/text/Base64.h"
 #include "wtf/text/WTFString.h"
 #include <algorithm>
 #include "RuntimeEnabledFeatures.h"
@@ -943,38 +942,6 @@ String DOMWindow::prompt(const String& message, const String& defaultValue)
     return String();
 }
 
-String DOMWindow::btoa(const String& stringToEncode, ExceptionCode& ec)
-{
-    if (stringToEncode.isNull())
-        return String();
-
-    if (!stringToEncode.containsOnlyLatin1()) {
-        ec = InvalidCharacterError;
-        return String();
-    }
-
-    return base64Encode(stringToEncode.latin1());
-}
-
-String DOMWindow::atob(const String& encodedString, ExceptionCode& ec)
-{
-    if (encodedString.isNull())
-        return String();
-
-    if (!encodedString.containsOnlyLatin1()) {
-        ec = InvalidCharacterError;
-        return String();
-    }
-
-    Vector<char> out;
-    if (!base64Decode(encodedString, out, Base64FailOnInvalidCharacter)) {
-        ec = InvalidCharacterError;
-        return String();
-    }
-
-    return String(out.data(), out.size());
-}
-
 bool DOMWindow::find(const String& string, bool caseSensitive, bool backwards, bool wrap, bool /*wholeWord*/, bool /*searchInFrames*/, bool /*showDialog*/) const
 {
     if (!isCurrentlyDisplayedInFrame())