[filesapp] Add volume manager shouldProvideIcons helper

The iconSet property of most volume types is empty, but we expect that
third party volumes (ANDROID_FILES, DOCUMENT_PROVIDERS and File System
Providers) should provide icons in the respective iconSets.

Add a shouldProvideIcons() helper to volume manager common, that lists
the volumes types that should provide icons.

Bug: 992819
Change-Id: I00b9d1910ff9069fb82d1a51519f0dc72d2c81a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2032469
Commit-Queue: Alex Danilo <adanilo@chromium.org>
Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Reviewed-by: Alex Danilo <adanilo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737224}

ui/file_manager/base/js/volume_manager_types.js

@@ -290,10 +290,12 @@ VolumeManagerCommon.getVolumeTypeFromRootType = rootType => {
     case VolumeManagerCommon.RootType.SMB:
       return VolumeManagerCommon.VolumeType.SMB;
   }
+
   assertNotReached('Unknown root type: ' + rootType);
 };
 
 /**
+ * Obtains root type from volume type.
  * @param {VolumeManagerCommon.VolumeType} volumeType .
  * @return {VolumeManagerCommon.RootType}
  */
@@ -324,9 +326,33 @@ VolumeManagerCommon.getRootTypeFromVolumeType = volumeType => {
     case VolumeManagerCommon.VolumeType.SMB:
       return VolumeManagerCommon.RootType.SMB;
   }
+
   assertNotReached('Unknown volume type: ' + volumeType);
 };
 
+/**
+ * Returns true if the given |volumeType| is expected to provide third party
+ * icons in the iconSet property of the volume.
+ * @param {VolumeManagerCommon.VolumeType} volumeType
+ * @return {boolean}
+ */
+VolumeManagerCommon.shouldProvideIcons = volumeType => {
+  switch (volumeType) {
+    case VolumeManagerCommon.VolumeType.ANDROID_FILES:
+      return true;
+    case VolumeManagerCommon.VolumeType.DOCUMENTS_PROVIDER:
+      return true;
+    case VolumeManagerCommon.VolumeType.PROVIDED:
+      return true;
+  }
+
+  if (!volumeType) {
+    assertNotReached('Invalid volume type: ' + volumeType);
+  }
+
+  return false;
+};
+
 /**
  * List of media view root types.
  *