Fix Downloads path when MyFilesVolume is enabled

When MyFilesVolume is enabled and the its volume is already mounted
|GetDownloadsFolderForProfile| was returning actually MyFiles path
instead of MyFiles/Downloads path, this CL fixes this.

Bug: 873539
Change-Id: I099f788a6d067dce4857a6b4946808559799b45d
Reviewed-on: https://chromium-review.googlesource.com/c/1352070Reviewed-by: Joel Hockey <joelhockey@chromium.org>
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611504}

chrome/browser/chromeos/file_manager/path_util.cc

@@ -115,8 +115,12 @@ base::FilePath GetDownloadsFolderForProfile(Profile* profile) {
   storage::ExternalMountPoints* const mount_points =
       storage::ExternalMountPoints::GetSystemInstance();
   base::FilePath path;
-  if (mount_points->GetRegisteredPath(mount_point_name, &path))
+  if (mount_points->GetRegisteredPath(mount_point_name, &path)) {
+    if (base::FeatureList::IsEnabled(chromeos::features::kMyFilesVolume))
+      return path.AppendASCII(kFolderNameDownloads);
+
     return path;
+  }
 
   // Return $HOME/Downloads as Download folder.
   if (ShouldMountPrimaryUserDownloads(profile))

chrome/browser/chromeos/file_manager/path_util_unittest.cc

@@ -87,10 +87,6 @@ TEST(FileManagerPathUtilTest, GetMyFilesFolderForProfile) {
     base::test::ScopedFeatureList feature_list;
     feature_list.InitAndEnableFeature(chromeos::features::kMyFilesVolume);
 
-    base::FilePath myfiles_path = profile_path.AppendASCII("MyFiles");
-    base::FilePath myfiles_downloads_path =
-        myfiles_path.AppendASCII("Downloads");
-
     EXPECT_EQ("/home/chronos/u-0123456789abcdef/MyFiles",
               GetMyFilesFolderForProfile(&profile).value());
     EXPECT_EQ("/home/chronos/u-0123456789abcdef/MyFiles/Downloads",
@@ -102,10 +98,39 @@ TEST(FileManagerPathUtilTest, GetMyFilesFolderForProfile) {
         storage::kFileSystemTypeNativeLocal, storage::FileSystemMountOption(),
         profile_path.Append("MyFiles"));
 
+    // When returning from the mount_point Downloads should still point to
+    // MyFiles/Downloads.
+    EXPECT_EQ("/home/chronos/u-0123456789abcdef/MyFiles/Downloads",
+              GetDownloadsFolderForProfile(&profile).value());
+
     // Still the same: /home/u-{hash}/MyFiles.
     EXPECT_EQ("/home/chronos/u-0123456789abcdef/MyFiles",
               GetMyFilesFolderForProfile(&profile).value());
   }
+  {
+    // Remove mount configured to MyFiles in the previous test.
+    storage::ExternalMountPoints::GetSystemInstance()->RevokeFileSystem(
+        GetDownloadsMountPointName(&profile));
+
+    // Add mount point for Downloads instead of MyFiles.
+    storage::ExternalMountPoints::GetSystemInstance()->RegisterFileSystem(
+        GetDownloadsMountPointName(&profile),
+        storage::kFileSystemTypeNativeLocal, storage::FileSystemMountOption(),
+        profile_path.Append("Downloads"));
+
+    // Disable MyFilesVolume again to test returning from the mount_point.
+    base::test::ScopedFeatureList feature_list;
+    feature_list.InitAndDisableFeature(chromeos::features::kMyFilesVolume);
+    // When MyFilesVolume feature is disabled it will return the same as
+    // Downloads.
+    EXPECT_EQ(GetDownloadsFolderForProfile(&profile),
+              GetMyFilesFolderForProfile(&profile));
+    EXPECT_EQ("/home/chronos/u-0123456789abcdef/Downloads",
+              GetDownloadsFolderForProfile(&profile).value());
+    // Unmount Downloads because it was interfering with other tests.
+    storage::ExternalMountPoints::GetSystemInstance()->RevokeFileSystem(
+        GetDownloadsMountPointName(&profile));
+  }
 }
 
 TEST(FileManagerPathUtilTest, GetPathDisplayTextForSettings) {