Move StringPiece into the base namespace. It is colliding

base/string_piece_unittest.cc

 // Copyright (c) 2006-2008 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 <string>
 
 #include "base/string_piece.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 
+using namespace base;
+
 TEST(StringPieceTest, CheckComparisonOperators) {
 #define CMP_Y(op, x, y)                                               \
   ASSERT_TRUE( (StringPiece((x)) op StringPiece((y))));               \
   ASSERT_TRUE( (StringPiece((x)).compare(StringPiece((y))) op 0))
 
 #define CMP_N(op, x, y)                                          \
   ASSERT_FALSE(StringPiece((x)) op StringPiece((y)));               \
   ASSERT_FALSE(StringPiece((x)).compare(StringPiece((y))) op 0)
 
   CMP_Y(==, "",   "");
@@ skipping 510 matching lines @@
 
 TEST(StringPieceTest, StringCompareNotAmbiguous) {
   ASSERT_TRUE("hello" == std::string("hello"));
   ASSERT_TRUE("hello" < std::string("world"));
 }
 
 TEST(StringPieceTest, HeterogenousStringPieceEquals) {
   ASSERT_TRUE(StringPiece("hello") == std::string("hello"));
   ASSERT_TRUE("hello" == StringPiece("hello"));
 }