Bind Win32 app shell and move more legacy platform state

src/platform_legacy/legacy_platform_state.cpp

@@ -10,6 +10,12 @@
 #include <GLFW/glfw3.h>
 #endif
 
+void webgl_pick_file_save(
+    const std::string& path,
+    const std::string& name,
+    std::function<void(bool)> callback);
+void webgl_sync();
+
 namespace pp::platform::legacy {
 namespace {
 
@@ -204,6 +210,43 @@ struct RetainedLegacyAppleDocumentPlatformState final {
 }
 #endif
 
+class RetainedWebPlatformServices final : public pp::platform::WebPlatformServices {
+public:
+    void publish_exported_image(std::string_view path) override
+    {
+        (void)path;
+    }
+
+    void flush_persistent_storage() override
+    {
+#ifdef __WEB__
+        webgl_sync();
+#endif
+    }
+
+    [[nodiscard]] int default_canvas_resolution() override
+    {
+        return pp::platform::platform_default_canvas_resolution(pp::platform::PlatformFamily::webgl);
+    }
+
+    void save_prepared_file(
+        std::string_view path,
+        std::string_view suggested_name,
+        pp::platform::PreparedFileCallback callback) override
+    {
+        const std::string value(path);
+        const std::string name(suggested_name);
+#ifdef __WEB__
+        webgl_pick_file_save(value, name, [callback = std::move(callback), value](bool success) {
+            callback(value, success);
+        });
+#else
+        (void)name;
+        callback(value, false);
+#endif
+    }
+};
+
 }
 
 #if defined(__LINUX__) || defined(__WEB__)
@@ -254,6 +297,17 @@ active_legacy_apple_document_platform_services()
     return *retained.services;
 }
 
+[[nodiscard]] pp::platform::PlatformStoragePaths prepare_legacy_apple_storage_paths()
+{
+    const auto& apple_state = active_legacy_apple_state();
+#ifdef __IOS__
+    [apple_state.ios_view init_dirs];
+#elif defined(__OSX__)
+    [apple_state.osx_app init_dirs];
+#endif
+    return active_legacy_storage_paths();
+}
+
 void set_legacy_apple_state(
 #ifdef __IOS__
     GameViewController* ios_view,
@@ -294,6 +348,12 @@ void set_legacy_apple_state(
 }
 #endif
 
+[[nodiscard]] pp::platform::WebPlatformServices& active_legacy_web_platform_services()
+{
+    static RetainedWebPlatformServices services;
+    return pp::platform::resolve_web_platform_services(services);
+}
+
 [[nodiscard]] const pp::platform::PlatformStoragePaths& active_legacy_storage_paths()
 {
     return retained_legacy_storage_paths().storage_paths;