desktop-pwas: Add OsSupportsWebAppFileHandling() method, remove #ifdef OS_WIN

Bug: 960245
Change-Id: Ia1309ec99b1518aa7371fa24130c71662eb332cc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1823725
Commit-Queue: David Bienvenu <davidbienvenu@chromium.org>
Reviewed-by: Alexey Baskakov <loyso@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700432}

chrome/browser/web_applications/components/BUILD.gn

@@ -39,6 +39,7 @@ source_set("components") {
     "web_app_constants.h",
     "web_app_data_retriever.cc",
     "web_app_data_retriever.h",
+    "web_app_file_extension_registration.cc",
     "web_app_file_extension_registration.h",
     "web_app_file_extension_registration_win.cc",
     "web_app_helpers.cc",

chrome/browser/web_applications/components/file_handler_manager.cc

@@ -5,7 +5,6 @@
 #include "chrome/browser/web_applications/components/file_handler_manager.h"
 
 #include "base/feature_list.h"
-#include "build/build_config.h"
 #include "chrome/browser/web_applications/components/web_app_file_extension_registration.h"
 #include "third_party/blink/public/common/features.h"
 
@@ -22,8 +21,8 @@ void FileHandlerManager::SetSubsystems(AppRegistrar* registrar) {
 }
 
 void FileHandlerManager::OnWebAppInstalled(const AppId& installed_app_id) {
-#if defined(OS_WIN)
-  if (!base::FeatureList::IsEnabled(blink::features::kFileHandlingAPI))
+  if (!base::FeatureList::IsEnabled(blink::features::kFileHandlingAPI) ||
+      !OsSupportsWebAppFileHandling())
     return;
   std::string app_name = registrar_->GetAppShortName(installed_app_id);
   const std::vector<apps::FileHandlerInfo>* file_handlers =
@@ -34,13 +33,13 @@ void FileHandlerManager::OnWebAppInstalled(const AppId& installed_app_id) {
       GetFileExtensionsFromFileHandlers(*file_handlers);
   RegisterFileHandlersForWebApp(installed_app_id, app_name, *profile_,
                                 file_extensions);
-#endif  // OS_WIN
 }
 
 void FileHandlerManager::OnWebAppUninstalled(const AppId& installed_app_id) {
-#if defined(OS_WIN)
-  UnregisterFileHandlersForWebApp(installed_app_id, *profile_);
-#endif  // OS_WIN
+  if (base::FeatureList::IsEnabled(blink::features::kFileHandlingAPI) &&
+      OsSupportsWebAppFileHandling()) {
+    UnregisterFileHandlersForWebApp(installed_app_id, *profile_);
+  }
 }
 
 void FileHandlerManager::OnAppRegistrarDestroyed() {

chrome/browser/web_applications/components/web_app_file_extension_registration.cc

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/web_applications/components/web_app_file_extension_registration.h"
+
+#include "base/logging.h"
+#include "build/build_config.h"
+
+namespace web_app {
+
+#if !defined(OS_WIN)
+bool OsSupportsWebAppFileHandling() {
+  return false;
+}
+
+void RegisterFileHandlersForWebApp(
+    const AppId& app_id,
+    const std::string& app_name,
+    const Profile& profile,
+    const std::set<std::string>& file_extensions) {
+  DCHECK(OsSupportsWebAppFileHandling());
+  // Stub function for OS's that don't support Web App file handling yet.
+}
+
+void UnregisterFileHandlersForWebApp(const AppId& app_id,
+                                     const Profile& profile) {
+  DCHECK(OsSupportsWebAppFileHandling());
+  // Stub function for OS's that don't support Web App file handling yet.
+}
+#endif
+
+}  // namespace web_app

chrome/browser/web_applications/components/web_app_file_extension_registration.h

@@ -14,6 +14,9 @@ class Profile;
 
 namespace web_app {
 
+// returns true if Chrome supports WebApp File Handling on this OS.
+bool OsSupportsWebAppFileHandling();
+
 // Do OS-specific registration to handle opening files with the specified
 // |file_extensions| with the PWA with the specified |app_id|.
 // This may also involve creating a shim app to launch Chrome from.

chrome/browser/web_applications/components/web_app_file_extension_registration_win.cc

@@ -8,6 +8,10 @@
 
 namespace web_app {
 
+bool OsSupportsWebAppFileHandling() {
+  return true;
+}
+
 void RegisterFileHandlersForWebApp(
     const AppId& app_id,
     const std::string& app_name,