--- a/dom/webidl/WebGL2RenderingContext.webidl
+++ b/dom/webidl/WebGL2RenderingContext.webidl
@@ -299,24 +299,24 @@ interface WebGL2RenderingContext : WebGL
 
     /* WebGL-specific enums */
     const GLenum MAX_CLIENT_WAIT_TIMEOUT_WEBGL                 = 0x9247;
 
     /* Buffer objects */
     // WebGL1:
     void bufferData(GLenum target, GLsizeiptr size, GLenum usage);
     void bufferData(GLenum target, ArrayBuffer? srcData, GLenum usage);
-    void bufferData(GLenum target, ArrayBufferView srcData, GLenum usage);
+    //void bufferData(GLenum target, ArrayBufferView srcData, GLenum usage);
     void bufferSubData(GLenum target, GLintptr offset, ArrayBuffer srcData);
-    void bufferSubData(GLenum target, GLintptr offset, ArrayBufferView srcData);
+    //void bufferSubData(GLenum target, GLintptr offset, ArrayBufferView srcData);
     // WebGL2:
-    void bufferData(GLenum target, ArrayBufferView srcData, GLenum usage, GLuint srcOffset,
-                    optional GLuint length = 0);
+    void bufferData(GLenum target, ArrayBufferView srcData, GLenum usage,
+                    optional GLuint srcOffset = 0, optional GLuint length = 0);
     void bufferSubData(GLenum target, GLintptr dstByteOffset, ArrayBufferView srcData,
-                       GLuint srcOffset, optional GLuint length = 0);
+                       optional GLuint srcOffset = 0, optional GLuint length = 0);
 
     void copyBufferSubData(GLenum readTarget, GLenum writeTarget, GLintptr readOffset,
                            GLintptr writeOffset, GLsizeiptr size);
     // MapBufferRange, in particular its read-only and write-only modes,
     // can not be exposed safely to JavaScript. GetBufferSubData
     // replaces it for the purpose of fetching data back from the GPU.
     void getBufferSubData(GLenum target, GLintptr srcByteOffset, ArrayBufferView dstData,
                           optional GLuint dstOffset = 0, optional GLuint length = 0);
@@ -612,17 +612,17 @@ interface WebGL2RenderingContext : WebGL
     void clearBufferfi(GLenum buffer, GLint drawbuffer, GLfloat depth, GLint stencil);
 
     /* Query Objects */
     WebGLQuery? createQuery();
     void deleteQuery(WebGLQuery? query);
     [WebGLHandlesContextLoss] GLboolean isQuery(WebGLQuery? query);
     void beginQuery(GLenum target, WebGLQuery query);
     void endQuery(GLenum target);
-    WebGLQuery? getQuery(GLenum target, GLenum pname);
+    any getQuery(GLenum target, GLenum pname);
     any getQueryParameter(WebGLQuery query, GLenum pname);
 
     /* Sampler Objects */
     WebGLSampler? createSampler();
     void deleteSampler(WebGLSampler? sampler);
     [WebGLHandlesContextLoss] GLboolean isSampler(WebGLSampler? sampler);
     void bindSampler(GLuint unit, WebGLSampler? sampler);
     void samplerParameteri(WebGLSampler sampler, GLenum pname, GLint param);