Don't use the same fake App ID for all test apps

A follow-up commit will use the IDs as a map key, to de-duplicate
installation tasks and avoid re-installing a web app that's already
installed. That requires that different web apps have different IDs.

Change-Id: I8a86e6cd20ed59a2f5df0683353935004a2c39a5
Reviewed-on: https://chromium-review.googlesource.com/1186927Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Commit-Queue: Nigel Tao <nigeltao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585693}

chrome/browser/web_applications/extensions/pending_bookmark_app_manager_unittest.cc

@@ -63,13 +63,15 @@ class TestBookmarkAppInstallationTask : public BookmarkAppInstallationTask {
   void InstallWebAppOrShortcutFromWebContents(
       content::WebContents* web_contents,
       BookmarkAppInstallationTask::ResultCallback callback) override {
+    BookmarkAppInstallationTask::ResultCode result_code =
+        BookmarkAppInstallationTask::ResultCode::kInstallationFailed;
+    std::string app_id;
+    if (succeeds_) {
+      result_code = BookmarkAppInstallationTask::ResultCode::kSuccess;
+      app_id = "fake_app_id_for:" + app_info().url.spec();
+    }
     std::move(callback).Run(
-        succeeds_
-            ? BookmarkAppInstallationTask::Result(
-                  BookmarkAppInstallationTask::ResultCode::kSuccess, "12345")
-            : BookmarkAppInstallationTask::Result(
-                  BookmarkAppInstallationTask::ResultCode::kInstallationFailed,
-                  std::string()));
+        BookmarkAppInstallationTask::Result(result_code, app_id));
   }
 
  private: