Don't populate URL data in WebDropData when dragging files.

This is considered a potential security issue as well, since it leaks
filesystem paths.

BUG=332579

Review URL: https://codereview.chromium.org/135633002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244538 0039d316-1c4b-4281-b951-d872f2087c98
void OSExchangeDataProviderAura::SetDragImage(
    const gfx::ImageSkia& image,
    const gfx::Vector2d& cursor_offset) {
  drag_image_ = image;
  drag_image_offset_ = cursor_offset;
}

void OSExchangeDataProviderAura::SetDragImage(
    const gfx::ImageSkia& image,
    const gfx::Vector2d& cursor_offset) {
  drag_image_ = image;
  drag_image_offset_ = cursor_offset;
}
