Fix SetShape (SetAlphaShape) to allow Null regions (+ tests).

chrome/browser/extensions/api/app_window/app_window_apitest.cc

Index: chrome/browser/extensions/api/app_window/app_window_apitest.cc
diff --git a/chrome/browser/extensions/api/app_window/app_window_apitest.cc b/chrome/browser/extensions/api/app_window/app_window_apitest.cc
index 2420628ad7a3ddee05b023b3ca3da34554dea3d7..39b8e4a0097e4ffcfdac8f8b23b1bcfdc5755ab5 100644
--- a/chrome/browser/extensions/api/app_window/app_window_apitest.cc
+++ b/chrome/browser/extensions/api/app_window/app_window_apitest.cc
@@ -110,4 +110,9 @@ IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, WindowsApiGet) {
       << message_;
 }
 
+IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, WindowsApiSetShape) {
+  EXPECT_TRUE(RunPlatformAppTest("platform_apps/windows_api_shape"))
+      << message_;
+}
+
 }  // namespace extensions