Bug 1228949 - Fix WebGLBuffer content type when the target is LOCAL_GL_COPY_READ_BUFFER or LOCAL_GL_COPY_WRITE_BUFFER. r=jgilbert

dom/canvas/WebGLBuffer.cpp

@@ -46,7 +46,9 @@ WebGLBuffer::BindTo(GLenum target)
 
     case LOCAL_GL_COPY_READ_BUFFER:
     case LOCAL_GL_COPY_WRITE_BUFFER:
-        /* Do nothing. Doesn't set the type of the buffer contents. */
+        if (mContent == Kind::Undefined) {
+          mContent = Kind::OtherData;
+        }
         break;
 
     default: