canvas: Make OffscreenCanvas transferable (without placeholder) (#37872)

Follow the specification and make OffscreenCanvas objects are
transferable,
but not in case if there are a weak reference to placeholder canvas
element.
To handle it properly need to implement dedicated frame
provider/dispatcher
between canvas element (script thread) and offscreen canvas (dedicated
worker thread).

https://html.spec.whatwg.org/multipage/#the-offscreencanvas-interface:transferable-objects

Testing: Improvements in the following tests
-
html/canvas/element/drawing-images-to-the-canvas/2d.drawImage.detachedcanvas.html
-
html/canvas/offscreen/manual/convert-to-blob/offscreencanvas.convert.to.blob*
-
html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer*
-
html/infrastructure/safe-passing-of-structured-data/transfer-errors.window.js

Part of #24276

Signed-off-by: Andrei Volykhin <andrei.volykhin@gmail.com>

components/script_bindings/webidls/OffscreenCanvas.webidl

@@ -13,7 +13,7 @@ dictionary ImageEncodeOptions {
 
 //enum OffscreenRenderingContextId { "2d", "webgl", "webgl2" };
 
-[Exposed=(Window,Worker)/*, Transferable*/, Pref="dom_offscreen_canvas_enabled"]
+[Exposed=(Window,Worker), Transferable, Pref="dom_offscreen_canvas_enabled"]
 interface OffscreenCanvas : EventTarget {
   [Throws] constructor([EnforceRange] unsigned long long width, [EnforceRange] unsigned long long height);
   attribute [EnforceRange] unsigned long long width;