API Review: CustomDefaultDownloadLocation.md (#1977)

* Add spec for CustomDefaultDownloadLocation.md (#1947)

* Revert "switch design to corner enum + offset"

This reverts commit 4520cc7.

* API Review: DefaultDownloadDialog.md (#1770)

* (Draft) API Review: DefaultDownloadDialog.md

* switch to enum + offset design

* change method to two properties and offset to padding

* add event for IsDefaultDownloadDialogOpenChanged

* use point for margin and renaming

Co-authored-by: Viktoria Zlatinova <vizlatin@microsoft.com>

* API review updates

* use ShowDownloadsToggleButton

* Api review: Custom default download location (draft)

* update docs

* update docs

* Update specs/CustomDefaultDownloadLocation.md

Co-authored-by: David Risney <dave@deletethis.net>

* indent and move block to end

* update docs

Co-authored-by: Viktoria Zlatinova <vizlatin@microsoft.com>
Co-authored-by: David Risney <dave@deletethis.net>

* rename and document timing

* update docs on how user can override path

* delete old spec copy

* matching sample code

Co-authored-by: Viktoria Zlatinova <vizlatin@microsoft.com>
Co-authored-by: David Risney <dave@deletethis.net>

Author: vickiez

specs/CustomDefaultDownloadLocation.md

@@ -0,0 +1,84 @@
+Custom Default Download Location
+===
+
+# Background
+This API allows you to set a custom default download location per profile. The
+user can still change the path through the Save As dialog.
+
+In this document we describe the updated API. We'd appreciate your feedback.
+
+# Examples
+```cpp
+HRESULT AppWindow::OnCreateCoreWebView2ControllerCompleted(
+    HRESULT result, ICoreWebView2Controller* controller)
+{
+    if (result == S_OK)
+    {
+        if (!m_webviewOption.downloadPath.empty())
+        {
+            Microsoft::WRL::ComPtr<ICoreWebView2Profile2> profile2;
+            CHECK_FAILURE(m_profile->QueryInterface(IID_PPV_ARGS(
+                &profile2)));
+            CHECK_FAILURE(profile2->put_DefaultDownloadFolderPath(
+                m_webviewOption.downloadPath.c_str()));
+        }
+    }
+}
+```
+```c#
+void WebView_CoreWebView2InitializationCompleted(object sender,
+    CoreWebView2InitializationCompletedEventArgs e)
+{
+    if (e.IsSuccess)
+    {
+        if (!string.IsNullOrEmpty(_downloadPath))
+        {
+            WebViewProfile.DefaultDownloadFolderPath = _downloadPath;
+        }
+    }
+}
+```
+# API Details
+```c#
+/// This is a continuation of the `ICoreWebView2Profile` interface.
+[uuid(DAF8B1F9-276D-410C-B481-58CBADF85C9C), object, pointer_default(unique)]
+interface ICoreWebView2Profile2 : ICoreWebView2Profile {
+  /// Gets the `DefaultDownloadFolderPath` property. The default value is the
+  /// system default download folder path for the user.
+  [propget] HRESULT DefaultDownloadFolderPath([out, retval] LPWSTR* value);
+
+  /// Sets the `DefaultDownloadFolderPath` property. The default download folder
+  /// path is persisted in the user data folder across sessions. The value
+  /// should be an absolute path to a folder that the user and application can
+  /// write to. Returns `E_INVALIDARG` if the value is invalid, and the default
+  /// download folder path is not changed. Otherwise the path is changed
+  /// immediately. If the directory does not yet exist, it is created at the
+  /// time of the next download. If the host application does not have
+  /// permission to create the directory, then the user is prompted to provide a
+  /// new path through the Save As dialog. The user can override the default
+  /// download folder path for a given download by choosing a different path in
+  /// the Save As dialog.
+  [propput] HRESULT DefaultDownloadFolderPath([in] LPCWSTR value);
+}
+```
+```c#
+namespace Microsoft.Web.WebView2.Core
+{
+    runtimeclass CoreWebView2Profile
+    {
+        // The following properties already exist.
+        // String ProfileName { get; };
+        // Boolean IsInPrivateModeEnabled { get; };
+        // String ProfilePath { get; };
+
+        // The following method already exists.
+        // Windows.Foundation.IAsyncOperation<Boolean> ClearBrowsingDataAsync(
+        //     UInt64 dataKinds, Double startTime, Double endTime);
+
+        [interface_name("Microsoft.Web.WebView2.Core.ICoreWebView2Profile2")]
+        {
+            String DefaultDownloadFolderPath { get; set; };
+        }
+    }
+}
+```