WebApps: Fixes issue where web app installation would never succeed.

This only affected the new apps installed on the new WebApps system and
was caused because the create shortcuts callback would never fire (as
the method was not implemented). The fix is to set 'CanCreateShortcuts'
to false for the new system.

Bug: 860581
Change-Id: I64c560f58a53b4643daed4c9dc072b3c762e383f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1885132Reviewed-by: Alexey Baskakov <loyso@chromium.org>
Commit-Queue: Jay Harris <harrisjay@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710169}

chrome/browser/web_applications/components/app_shortcut_manager.h

@@ -37,7 +37,6 @@ class AppShortcutManager {
   void AddObserver(AppShortcutObserver* observer);
   void RemoveObserver(AppShortcutObserver* observer);
 
-  // virtual for testing.
   virtual bool CanCreateShortcuts() const;
 
   // virtual for testing.

chrome/browser/web_applications/web_app_shortcut_manager.cc

@@ -13,6 +13,11 @@ WebAppShortcutManager::WebAppShortcutManager(Profile* profile)
 
 WebAppShortcutManager::~WebAppShortcutManager() = default;
 
+bool WebAppShortcutManager::CanCreateShortcuts() const {
+  NOTIMPLEMENTED();
+  return false;
+}
+
 void WebAppShortcutManager::GetShortcutInfoForApp(
     const AppId& app_id,
     GetShortcutInfoCallback callback) {

chrome/browser/web_applications/web_app_shortcut_manager.h

@@ -17,6 +17,8 @@ class WebAppShortcutManager : public AppShortcutManager {
   explicit WebAppShortcutManager(Profile* profile);
   ~WebAppShortcutManager() override;
 
+  bool CanCreateShortcuts() const override;
+
   void GetShortcutInfoForApp(const AppId& app_id,
                              GetShortcutInfoCallback callback) override;