base: Update the include paths of base/string_piece.h to its new location.

base/android/jni_string.h

 // 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.
 
 #ifndef BASE_ANDROID_JNI_STRING_H_
 #define BASE_ANDROID_JNI_STRING_H_
 
 #include <jni.h>
 #include <string>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/base_export.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 
 namespace base {
 namespace android {
 
 // Convert a Java string to UTF8. Returns a std string.
 BASE_EXPORT void ConvertJavaStringToUTF8(JNIEnv* env,
                                          jstring str,
                                          std::string* result);
 BASE_EXPORT std::string ConvertJavaStringToUTF8(JNIEnv* env, jstring str);
 BASE_EXPORT std::string ConvertJavaStringToUTF8(const JavaRef<jstring>& str);
@@ skipping 12 matching lines @@
 
 // Convert a string16 to a Java string.
 BASE_EXPORT ScopedJavaLocalRef<jstring> ConvertUTF16ToJavaString(
     JNIEnv* env,
     const base::StringPiece16& str);
 
 }  // namespace android
 }  // namespace base
 
 #endif  // BASE_ANDROID_JNI_STRING_H_