Use base namespace for string16 in chrome/renderer.

chrome/renderer/spellchecker/spellcheck_provider_hunspell_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 <vector>
 
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/common/spellcheck_marker.h"
 #include "chrome/common/spellcheck_messages.h"
@@ skipping 114 matching lines @@
   EXPECT_EQ(completion.completion_count_, 4U);
   EXPECT_EQ(completion.cancellation_count_, 1U);
   EXPECT_EQ(provider_.spelling_service_call_count_, 2U);
 }
 
 // Tests that the SpellCheckProvider calls didFinishCheckingText() when
 // necessary.
 TEST_F(SpellCheckProviderTest, CompleteNecessaryRequests) {
   FakeTextCheckingCompletion completion;
 
-  string16 text = ASCIIToUTF16("Icland is an icland ");
+  base::string16 text = ASCIIToUTF16("Icland is an icland ");
   provider_.RequestTextChecking(
       blink::WebString(text), &completion, std::vector<SpellCheckMarker>());
   EXPECT_EQ(0U, completion.cancellation_count_) << "Should finish checking \""
                                                 << text << "\"";
 
   const int kSubstringLength = 18;
-  string16 substring = text.substr(0, kSubstringLength);
+  base::string16 substring = text.substr(0, kSubstringLength);
   provider_.RequestTextChecking(blink::WebString(substring),
                                 &completion,
                                 std::vector<SpellCheckMarker>());
   EXPECT_EQ(0U, completion.cancellation_count_) << "Should finish checking \""
                                                 << substring << "\"";
 
   provider_.RequestTextChecking(
       blink::WebString(text), &completion, std::vector<SpellCheckMarker>());
   EXPECT_EQ(0U, completion.cancellation_count_) << "Should finish checking \""
                                                 << text << "\"";
@@ skipping 19 matching lines @@
 
   provider_.RequestTextChecking(blink::WebString("hello world."),
                                 &completion,
                                 std::vector<SpellCheckMarker>());
   EXPECT_EQ(completion.completion_count_, 3U);
   EXPECT_EQ(completion.cancellation_count_, 1U);
   EXPECT_EQ(provider_.spelling_service_call_count_, 2U);
 }
 
 }  // namespace