WebShare: Stub implementation for Windows

Adding a stub implementation of the mojom ShareService. Currently only
for the Windows build, but intended to be useable as the central file
from which OS-specific implementations can be connected (e.g. a future
share_service_imple_win for the Windows-specific implementation).

To exercise this code, enable the Web Share flag in chrome://flags,
navigate to https://w3c.github.io/web-share/demos/share-files.html, and
attempt to Share content.  With this change, calls to navigator.share
are completed with a cancellation error, rather than crashing the
process.

Bug: 1035527
Change-Id: Id01c2a49646fc9e64401f34fe886b2527866ebda
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2378144Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Reviewed-by: Eric Willigers <ericwilligers@chromium.org>
Commit-Queue: Eric Willigers <ericwilligers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803103}

chrome/browser/BUILD.gn

@@ -4224,6 +4224,8 @@ static_library("browser") {
       "themes/theme_helper_win.cc",
       "themes/theme_helper_win.h",
       "upgrade_detector/get_installed_version_win.cc",
+      "webshare/share_service_impl.cc",
+      "webshare/share_service_impl.h",
       "win/app_icon.cc",
       "win/app_icon.h",
       "win/automation_controller.cc",

chrome/browser/chrome_browser_interface_binders.cc

@@ -38,6 +38,7 @@
 #include "chrome/browser/ui/webui/omnibox/omnibox_ui.h"
 #include "chrome/browser/ui/webui/usb_internals/usb_internals.mojom.h"
 #include "chrome/browser/ui/webui/usb_internals/usb_internals_ui.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/pref_names.h"
 #include "chromeos/constants/chromeos_features.h"
 #include "components/contextual_search/buildflags.h"
@@ -101,7 +102,6 @@
 #include "services/service_manager/public/cpp/interface_provider.h"
 #include "third_party/blink/public/mojom/digital_goods/digital_goods.mojom.h"
 #include "third_party/blink/public/mojom/installedapp/installed_app_provider.mojom.h"
-#include "third_party/blink/public/mojom/webshare/webshare.mojom.h"
 #else
 #include "chrome/browser/accessibility/caption_host_impl.h"
 #include "chrome/browser/badging/badge_manager.h"
@@ -184,6 +184,13 @@
 #include "media/capture/video/chromeos/mojom/camera_app.mojom.h"
 #endif
 
+#if defined(OS_WIN) || defined(OS_ANDROID)
+#if defined(OS_WIN)
+#include "chrome/browser/webshare/share_service_impl.h"
+#endif
+#include "third_party/blink/public/mojom/webshare/webshare.mojom.h"
+#endif
+
 #if defined(OS_CHROMEOS) && !defined(OFFICIAL_BUILD)
 #include "chromeos/components/telemetry_extension_ui/mojom/diagnostics_service.mojom.h"
 #include "chromeos/components/telemetry_extension_ui/mojom/probe_service.mojom.h"
@@ -474,6 +481,13 @@ void PopulateChromeFrameBinders(
       base::BindRepeating(&payments::CreatePaymentCredential));
 #endif
 
+#if defined(OS_WIN)
+  if (base::FeatureList::IsEnabled(features::kWebShare)) {
+    map->Add<blink::mojom::ShareService>(
+        base::BindRepeating(&ShareServiceImpl::Create));
+  }
+#endif
+
 #if BUILDFLAG(ENABLE_EXTENSIONS)
   map->Add<extensions::mime_handler::MimeHandlerService>(
       base::BindRepeating(&BindMimeHandlerService));

chrome/browser/webshare/share_service_impl.cc

+// Copyright 2020 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/webshare/share_service_impl.h"
+
+#include "mojo/public/cpp/bindings/self_owned_receiver.h"
+
+ShareServiceImpl::ShareServiceImpl() = default;
+ShareServiceImpl::~ShareServiceImpl() = default;
+
+// static
+void ShareServiceImpl::Create(
+    content::RenderFrameHost* render_frame_host,
+    mojo::PendingReceiver<blink::mojom::ShareService> receiver) {
+  mojo::MakeSelfOwnedReceiver(std::make_unique<ShareServiceImpl>(),
+                              std::move(receiver));
+}
+
+void ShareServiceImpl::Share(const std::string& title,
+                             const std::string& text,
+                             const GURL& share_url,
+                             std::vector<blink::mojom::SharedFilePtr> files,
+                             ShareCallback callback) {
+  // TODO(crbug.com/1035527): Add implementation for WIN_OS
+  NOTIMPLEMENTED();
+  std::move(callback).Run(blink::mojom::ShareError::CANCELED);
+}

chrome/browser/webshare/share_service_impl.h

+// Copyright 2020 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.
+
+#ifndef CHROME_BROWSER_WEBSHARE_SHARE_SERVICE_IMPL_H_
+#define CHROME_BROWSER_WEBSHARE_SHARE_SERVICE_IMPL_H_
+
+#include <string>
+#include <vector>
+
+#include "third_party/blink/public/mojom/webshare/webshare.mojom.h"
+
+class GURL;
+
+namespace content {
+class RenderFrameHost;
+}
+
+class ShareServiceImpl : public blink::mojom::ShareService {
+ public:
+  ShareServiceImpl();
+  ShareServiceImpl(const ShareServiceImpl&) = delete;
+  ShareServiceImpl& operator=(const ShareServiceImpl&) = delete;
+  ~ShareServiceImpl() override;
+
+  static void Create(
+      content::RenderFrameHost* render_frame_host,
+      mojo::PendingReceiver<blink::mojom::ShareService> receiver);
+
+  // blink::mojom::ShareService:
+  void Share(const std::string& title,
+             const std::string& text,
+             const GURL& share_url,
+             std::vector<blink::mojom::SharedFilePtr> files,
+             ShareCallback callback) override;
+};
+
+#endif  // CHROME_BROWSER_WEBSHARE_SHARE_SERVICE_IMPL_H_