Chrome Cleaner: Remove indirect base::FilePath mojo dependency.

components/chrome_cleaner/public/interfaces/chrome_prompt.mojom

 // Copyright 2017 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.
 
 module chrome_cleaner.mojom;
 
-import "mojo/common/file_path.mojom";
-
 [Extensible]
 enum PromptAcceptance {
   UNSPECIFIED = 0,
   // The Chrome prompt was not shown to the user (for example, due to an
   // experiment run that shouldn't prompt the user or because the user has
   // been prompted recently).
   NOT_SHOWN = 1,
   // The user explicitly accepted the Chrome prompt.
   ACCEPTED = 2,
   // The user explicitly denied the Chrome prompt.
   DENIED = 3,
   // The user didn't interact with the Chrome prompt after a while.
   IGNORED = 4,
 };
 
+struct FilePath {
+  // This isn't a string since Mojo strings must be valid utf8, and the paths
+  // aren't guaranteed to be valid utf8.

[Fabio Tirelo, 2017/06/12 14:04:50]

Mojo's string16 are also mapped to base. I think we should describe here as well
that we are only using primitive types to avoid version sheering of base.

[proberge, 2017/06/12 17:49:30]

Done.

+  array<uint16> value;
+};
+
 // Service provided by Chrome to prompt the user to start a cleanup if the
 // Chrome Cleanup Tool detects unwanted software on the system.
 interface ChromePrompt {
   // Params:
   //  - removable_uws_found: list of fully-qualified paths of the files that
   //                         will be deleted by the Chrome Cleanup Tool.
   // Returns:
   //  - prompt_acceptance: indicates if the user accepted the prompt.
-  PromptUser(array<mojo.common.mojom.FilePath> files_to_delete)
+  PromptUser(array<FilePath> files_to_delete)
       => (PromptAcceptance prompt_acceptance);
 };