uiautomationcore: Implement UIA_ProcessIdPropertyId for default HWND provider.

dlls/uiautomationcore/tests/uiautomation.c

@@ -12357,8 +12357,7 @@ static void test_node_hwnd_provider_(HUIANODE node, HWND hwnd, const char *file,
     winetest_push_context("UIA_ProcessIdPropertyId");
     hr = UiaGetPropertyValue(node, UIA_ProcessIdPropertyId, &v);
     ok_(file, line)(hr == S_OK, "Unexpected hr %#lx\n", hr);
-    todo_wine ok_(file, line)(V_VT(&v) == VT_I4, "Unexpected VT %d\n", V_VT(&v));
-    if (V_VT(&v) == VT_I4)
+    ok_(file, line)(V_VT(&v) == VT_I4, "Unexpected VT %d\n", V_VT(&v));
     ok_(file, line)(V_I4(&v) == pid, "V_I4(&v) = %#lx, expected %#lx\n", V_I4(&v), pid);
     VariantClear(&v);
     winetest_pop_context();

dlls/uiautomationcore/uia_provider.c

@@ -1292,6 +1292,18 @@ static HRESULT WINAPI base_hwnd_provider_GetPropertyValue(IRawElementProviderSim
         V_I4(ret_val) = HandleToUlong(base_hwnd_prov->hwnd);
         break;
 
+    case UIA_ProcessIdPropertyId:
+    {
+        DWORD pid;
+
+        if (!GetWindowThreadProcessId(base_hwnd_prov->hwnd, &pid))
+            return UIA_E_ELEMENTNOTAVAILABLE;
+
+        V_VT(ret_val) = VT_I4;
+        V_I4(ret_val) = pid;
+        break;
+    }
+
     default:
         break;
     }