dart2js + html: getBoundingClientRect() returns a ClientRect

tools/dom/scripts/dartmetadata.py

Index: tools/dom/scripts/dartmetadata.py
diff --git a/tools/dom/scripts/dartmetadata.py b/tools/dom/scripts/dartmetadata.py
index 7ec8331df2b54288efb4b619dbdb212c4d8801d2..efe5ab12482705a22dccfc383bba032377c5a42e 100644
--- a/tools/dom/scripts/dartmetadata.py
+++ b/tools/dom/scripts/dartmetadata.py
@@ -106,6 +106,11 @@ _dart2js_annotations = monitored.Dict('dartmetadata._dart2js_annotations', {
       "@Returns('NodeList')",
     ],
 
+    'Element.getBoundingClientRect': [
+        "@Creates('_ClientRect')",

[Jacob, 2017/05/15 21:59:53]

I don't think the return value from getBoundingClientRect
can really be null.
https://developer.mozilla.org/en-US/docs/Web/API/Element/getBoundingClientRect

[sra1, 2017/05/16 20:43:41]

I don't think it can be null, but I am going to play it safe.
For field accesses like .top, it does not make a difference in generated code
quality.

+        "@Returns('_ClientRect|Null')",
+    ],
+
     # Methods returning Window can return a local window, or a cross-frame
     # window (=Object) that needs wrapping.
     'Window': [