Use explicit WebString <-> string16 conversion methods in storage API files

third_party/WebKit/Source/platform/exported/FilePathConversionTest.cpp

 // Copyright 2016 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 "public/platform/FilePathConversion.h"
 
 #include "base/files/file_path.h"
 #include "public/platform/WebString.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "wtf/text/WTFString.h"
@@ skipping 22 matching lines @@
   EXPECT_FALSE(test16bitString.is8Bit());
   EXPECT_FALSE(test16bitLatin1.is8Bit());
 
   EXPECT_EQ(FILE_PATH_LITERAL("path"),
             WebStringToFilePath(test8bitString).value());
   EXPECT_EQ(pathLatin1.value(), WebStringToFilePath(test8bitLatin1).value());
   EXPECT_EQ(FILE_PATH_LITERAL("path"),
             WebStringToFilePath(test16bitString).value());
   EXPECT_EQ(pathLatin1.value(), WebStringToFilePath(test16bitLatin1).value());
   EXPECT_EQ(pathUTF16.value(), WebStringToFilePath(test16bitUTF16).value());
+
+  EXPECT_STREQ("path",
+               FilePathToWebString(base::FilePath(FILE_PATH_LITERAL("path")))
+                   .utf8()
+                   .data());
+  EXPECT_STREQ(test8bitLatin1.utf8().data(),
+               FilePathToWebString(pathLatin1).utf8().data());
+  EXPECT_STREQ(test16bitUTF16.utf8().data(),
+               FilePathToWebString(pathUTF16).utf8().data());
 }
 
 }  // namespace blink