Update some uses of char16 to use the base:: namespace.

ui/gfx/utf16_indexing_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/utf16_indexing.h"
 
 namespace gfx {
 
 TEST(UTF16IndexingTest, IndexOffsetConversions) {
   // Valid surrogate pair surrounded by unpaired surrogates
-  const char16 foo[] = {0xDC00, 0xD800, 0xD800, 0xDFFF, 0xDFFF, 0xDBFF, 0};
+  const base::char16 foo[] =
+      {0xDC00, 0xD800, 0xD800, 0xDFFF, 0xDFFF, 0xDBFF, 0};
   const base::string16 s(foo);
   const size_t the_invalid_index = 3;
   for (size_t i = 0; i <= s.length(); ++i)
     EXPECT_EQ(i != the_invalid_index, IsValidCodePointIndex(s, i));
   for (size_t i = 0; i <= s.length(); ++i) {
     for (size_t j = i; j <= s.length(); ++j) {
       ptrdiff_t offset = static_cast<ptrdiff_t>(j - i);
       if (i <= the_invalid_index && j > the_invalid_index)
         --offset;
       EXPECT_EQ(offset, UTF16IndexToOffset(s, i, j));
       EXPECT_EQ(-offset, UTF16IndexToOffset(s, j, i));
       size_t adjusted_j = (j == the_invalid_index) ? j + 1 : j;
       EXPECT_EQ(adjusted_j, UTF16OffsetToIndex(s, i, offset));
       size_t adjusted_i = (i == the_invalid_index) ? i + 1 : i;
       EXPECT_EQ(adjusted_i, UTF16OffsetToIndex(s, j, -offset));
     }
   }
 }
 
 }  // namespace gfx