Auto merge of #20669 - simartin:issue_20623, r=jdm

Issue #20623: Check the input to WebGLRenderingContext's clear().

Validate the input to this function as per specifications.

---
- [X] `./mach build -d` does not report any errors
- [X] `./mach build-geckolib` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #20623
- [X] There are tests for these changes

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components/script/dom/webglrenderingcontext.rs

@@ -1878,6 +1878,9 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
         if !self.validate_framebuffer_complete() {
             return;
         }
+        if mask & !(constants::DEPTH_BUFFER_BIT | constants::STENCIL_BUFFER_BIT | constants::COLOR_BUFFER_BIT) != 0 {
+            return self.webgl_error(InvalidValue);
+        }
 
         self.send_command(WebGLCommand::Clear(mask));
         self.mark_as_dirty();