WebGL 2: add types into glReadPixels

Source/modules/webgl/WebGLRenderingContextBase.h

Index: Source/modules/webgl/WebGLRenderingContextBase.h
diff --git a/Source/modules/webgl/WebGLRenderingContextBase.h b/Source/modules/webgl/WebGLRenderingContextBase.h
index 562bdca9c984ed0e1649eae46846724c8068580c..0eec8981b32b28aa214d68550c47326136cbc460 100644
--- a/Source/modules/webgl/WebGLRenderingContextBase.h
+++ b/Source/modules/webgl/WebGLRenderingContextBase.h
@@ -829,6 +829,9 @@ protected:
     // Generates INVALID_ENUM and returns false if parameters are invalid.
     virtual bool validateReadPixelsFormatAndType(GLenum format, GLenum type);
 
+    // Helper function to get expected ArrayBuffer view type for readPixels.
+    virtual DOMArrayBufferView::ViewType readPixelsExpectedArrayBufferViewType(GLenum type);
+
     // Helper function to check format/type combination for readPixels.
     // Generates INVALID_OPERATION and returns false if the combination is unsupported.
     bool validateReadPixelsFormatTypeCombination(GLenum format, GLenum type, GLenum readBufferInternalFormat, GLenum readBufferType);