Crostini share: fix unshare to work for filesystem roots

Fixed file_manager::path_util::ConvertFileSystemURLToPathsInsideCrostini
to correctly handle filesystem roots.

Added tests for path_util, and crostini unshare.

Bug: 907256
Change-Id: I0397c45330dae0d2a88f3d1f83c0a9c3a1349337
Reviewed-on: https://chromium-review.googlesource.com/c/1345379Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609900}

chrome/browser/chromeos/crostini/crostini_share_path_unittest.cc

@@ -516,6 +516,16 @@ TEST_F(CrostiniSharePathTest, UnsharePathSuccess) {
   run_loop()->Run();
 }
 
+TEST_F(CrostiniSharePathTest, UnsharePathRoot) {
+  crostini_share_path()->UnsharePath(
+      "vm-running", downloads_,
+      base::BindOnce(&CrostiniSharePathTest::UnsharePathCallback,
+                     base::Unretained(this), downloads_,
+                     SeneschalClientCalled::YES, "MyFiles/Downloads",
+                     Success::YES, ""));
+  run_loop()->Run();
+}
+
 TEST_F(CrostiniSharePathTest, UnsharePathVmNotRunning) {
   crostini_share_path()->UnsharePath(
       "vm-not-running", shared_path_,

chrome/browser/chromeos/file_manager/path_util.cc

@@ -227,7 +227,9 @@ bool ConvertFileSystemURLToPathInsideCrostini(
     const storage::FileSystemURL& file_system_url,
     base::FilePath* inside) {
   const std::string& id(file_system_url.mount_filesystem_id());
-  base::FilePath path(file_system_url.virtual_path());
+  // File system root requires strip trailing separator.
+  base::FilePath path =
+      base::FilePath(file_system_url.virtual_path()).StripTrailingSeparators();
   std::string mount_point_name_crostini = GetCrostiniMountPointName(profile);
   std::string mount_point_name_downloads = GetDownloadsMountPointName(profile);
   // Include drive if using DriveFS.
@@ -286,7 +288,8 @@ bool ConvertFileSystemURLToPathInsideCrostini(
   } else {
     return false;
   }
-  return base_to_exclude.AppendRelativePath(path, inside);
+  return base_to_exclude == path ||
+         base_to_exclude.AppendRelativePath(path, inside);
 }
 
 bool ConvertPathToArcUrl(const base::FilePath& path, GURL* arc_url_out) {

chrome/browser/chromeos/file_manager/path_util_unittest.cc

@@ -295,6 +295,23 @@ TEST(FileManagerPathUtilTest, ConvertFileSystemURLToPathInsideCrostini) {
     EXPECT_EQ("/mnt/chromeos/MyFiles/Downloads/path/in/downloads",
               inside.value());
 
+    EXPECT_TRUE(ConvertFileSystemURLToPathInsideCrostini(
+        &profile,
+        mount_points->CreateExternalFileSystemURL(
+            GURL(), "Downloads-testing_profile-hash",
+            base::FilePath("path/in/downloads/")),
+        &inside));
+
+    EXPECT_EQ("/mnt/chromeos/MyFiles/Downloads/path/in/downloads",
+              inside.value());
+
+    EXPECT_TRUE(ConvertFileSystemURLToPathInsideCrostini(
+        &profile,
+        mount_points->CreateExternalFileSystemURL(
+            GURL(), "Downloads-testing_profile-hash", base::FilePath()),
+        &inside));
+    EXPECT_EQ("/mnt/chromeos/MyFiles/Downloads", inside.value());
+
     EXPECT_FALSE(ConvertFileSystemURLToPathInsideCrostini(
         &profile,
         mount_points->CreateExternalFileSystemURL(