Split html library

[DartBot]

This issue was originally filed by [email protected]

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Currently there is a one huge file html_dartium.dart(1192 classes) that contains generated html stubs.

It would be great if you group some classes and extract them to separate files.

[DartBot]

This comment was originally written by @rbeeger

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Fedor's main motivation for this report is most likely that it takes some time for the IDEA Dart plugin to parse this file when it is opened.

But there is one more reason for splitting up this file. Separating it into several files based on the topic would help exploration of this part of dart's SDK.

So if I were interested in WebGL I would look into webgl.dart. For SVG I would look into svg.dart.

[DartBot]

This comment was originally written by @seaneagan

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this is a duplicate of issue #3108

[iposva-google]

Added Area-UI, Triaged labels.

[rakudrama]

Added Duplicate label.
Marked as being merged into #3108.