entries-api: Make webkitRelativePath interoperable

This CL makes webkitRelativePath IDL attribute behavior same as Edge,
Firefox, and Safari.  It returns relative path from the parent of the
selected directory.

* chrome/browser/file_select_helper.cc
* chrome/browser/file_select_helper.h
  Record a FilePath with which we started enumeration, and path it to
  FileSelectListener.

* android_webview/browser/aw_web_contents_delegate.cc
* chrome/browser/ssl/security_state_tab_helper_browsertest.cc
* content/browser/web_contents/web_contents_impl_browsertest.cc
* content/renderer/pepper/pepper_file_chooser_host_unittest.cc
* content/test/content_browser_test_utils_internal.cc
  Pass an empty FilePath to FileSelectListener.

* content/browser/frame_host/render_frame_host_impl.cc
* content/public/browser/file_select_listener.h
* third_party/blink/public/mojom/choosers/file_chooser.mojom
* third_party/blink/renderer/core/html/forms/file_chooser.h
* third_party/blink/renderer/core/html/forms/file_chooser.cc
  Pass a FilePath to FileInputType through FileSelectListener and mojo.

* third_party/blink/renderer/core/html/forms/file_input_type.cc
  Compute webkitRelativePath with the passed FilePath, instead of a
  common ancestor.

* third_party/WebKit/LayoutTests/fast/forms/resources/mock-file-chooser.js
  Support FileChooserResult.base_directory


Change-Id: I4c9f03b053b5a9230e954dcd216439d8c5c54d0b
Bug: 124187
Reviewed-on: https://chromium-review.googlesource.com/c/1325579
Commit-Queue: Kent Tamura <tkent@chromium.org>
Reviewed-by: Richard Coles <torne@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Joshua Bell <jsbell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607849}
24 files changed