Auto merge of #21313 - jdm:glstuff, r=nox

Framebuffer and renderbuffer fixes

This commits address two separate panics that occur when running the framebuffer-object-attachment.html test. The test still panics due to another framebuffer completion status problem, so the overall test results don't demonstrate any improvement.

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #21252
- [x] There are tests for these changes

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components/script/dom/webgl_extensions/ext/extshadertexturelod.rs

@@ -6,7 +6,7 @@ use canvas_traits::webgl::WebGLVersion;
 use dom::bindings::codegen::Bindings::EXTShaderTextureLodBinding;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
-use dom::webglrenderingcontext::WebGLRenderingContext;
+use dom::webglrenderingcontext::{WebGLRenderingContext, is_gles};
 use dom_struct::dom_struct;
 use super::{WebGLExtension, WebGLExtensions, WebGLExtensionSpec};
 
@@ -37,11 +37,8 @@ impl WebGLExtension for EXTShaderTextureLod {
     }
 
     fn is_supported(ext: &WebGLExtensions) -> bool {
-        if cfg!(any(target_os = "android", target_os = "ios")) {
-            return ext.supports_gl_extension("GL_EXT_shader_texture_lod");
-        }
         // This extension is always available on desktop GL.
-        true
+        !is_gles() || ext.supports_gl_extension("GL_EXT_shader_texture_lod")
     }
 
     fn enable(_ext: &WebGLExtensions) {}

components/script/dom/webgl_extensions/ext/oeselementindexuint.rs

@@ -6,7 +6,7 @@ use canvas_traits::webgl::WebGLVersion;
 use dom::bindings::codegen::Bindings::OESElementIndexUintBinding;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
-use dom::webglrenderingcontext::WebGLRenderingContext;
+use dom::webglrenderingcontext::{WebGLRenderingContext, is_gles};
 use dom_struct::dom_struct;
 use super::{WebGLExtension, WebGLExtensions, WebGLExtensionSpec};
 
@@ -37,11 +37,8 @@ impl WebGLExtension for OESElementIndexUint {
     }
 
     fn is_supported(ext: &WebGLExtensions) -> bool {
-        if cfg!(any(target_os = "android", target_os = "ios")) {
-            return ext.supports_gl_extension("GL_OES_element_index_uint");
-        }
         // This extension is always available in desktop OpenGL.
-        true
+        !is_gles() || ext.supports_gl_extension("GL_OES_element_index_uint")
     }
 
     fn enable(ext: &WebGLExtensions) {

components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs

@@ -7,7 +7,7 @@ use dom::bindings::codegen::Bindings::OESStandardDerivativesBinding;
 use dom::bindings::codegen::Bindings::OESStandardDerivativesBinding::OESStandardDerivativesConstants;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
-use dom::webglrenderingcontext::WebGLRenderingContext;
+use dom::webglrenderingcontext::{WebGLRenderingContext, is_gles};
 use dom_struct::dom_struct;
 use super::{WebGLExtension, WebGLExtensions, WebGLExtensionSpec};
 
@@ -37,11 +37,8 @@ impl WebGLExtension for OESStandardDerivatives {
     }
 
     fn is_supported(ext: &WebGLExtensions) -> bool {
-        if cfg!(any(target_os = "android", target_os = "ios")) {
-            return ext.supports_any_gl_extension(&["GL_OES_standard_derivatives"]);
-        }
         // The standard derivatives are always available in desktop OpenGL.
-        true
+        !is_gles() || ext.supports_any_gl_extension(&["GL_OES_standard_derivatives"])
     }
 
     fn enable(ext: &WebGLExtensions) {