Extension status returns blocked-by-policy when there is no manifest

When manifest type allowlist policy is set, GetExtensionInstallStatus()
function always returns blocked-by-policy when there is no manifest type
information. However, it should actually skip the manifest type check.

Add a test to verify the fix. Also add a test to verify we can handle
similar situation for permission set.

Bug: 1124669
Change-Id: I9727222688177a7beb386e5dc473ef21e766ce8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2392442Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Owen Min <zmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806407}

chrome/browser/extensions/api/webstore_private/extension_install_status.cc

@@ -51,7 +51,8 @@ bool IsExtensionInstallBlockedByPolicy(
   // and manifest type.
   // TODO(crbug.com/1088021): Find out the right way to handle extension policy
   // priority.
-  if (!extension_management->IsAllowedManifestType(manifest_type,
+  if (manifest_type != Manifest::Type::TYPE_UNKNOWN &&
+      !extension_management->IsAllowedManifestType(manifest_type,
                                                    extension_id)) {
     return true;
   }

chrome/browser/extensions/api/webstore_private/extension_install_status_unittest.cc

@@ -325,6 +325,27 @@ TEST_F(ExtensionInstallStatusTest, ExtensionBlockedByManifestType) {
                                               PermissionSet()));
 }
 
+TEST_F(ExtensionInstallStatusTest, ExtensionWithoutPermissionInfo) {
+  SetExtensionSettings(R"({
+    "*": {
+      "blocked_permissions": ["storage"]
+    }
+  })");
+
+  EXPECT_EQ(ExtensionInstallStatus::kInstallable,
+            GetWebstoreExtensionInstallStatus(kExtensionId, profile()));
+}
+
+TEST_F(ExtensionInstallStatusTest, ExtensionWithoutManifestInfo) {
+  SetExtensionSettings(R"({
+    "*": {
+      "allowed_types": ["theme"]
+    }
+  })");
+  EXPECT_EQ(ExtensionInstallStatus::kInstallable,
+            GetWebstoreExtensionInstallStatus(kExtensionId, profile()));
+}
+
 TEST_F(ExtensionInstallStatusTest, ExtensionBlockedByPermissions) {
   // Block 'storage' for all extensions.
   SetExtensionSettings(R"({