Upgrade WebGLImageConversion to support WebGL 2 formats and types.

Source/core/html/canvas/WebGLRenderingContextBase.cpp

Index: Source/core/html/canvas/WebGLRenderingContextBase.cpp
diff --git a/Source/core/html/canvas/WebGLRenderingContextBase.cpp b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
index 9d6a9ace57765c7b1ceb41bb2c626508620b71b2..36d3b7cffe30acfa6f3503bb1bc92ad596cd6e51 100644
--- a/Source/core/html/canvas/WebGLRenderingContextBase.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
@@ -1550,7 +1550,7 @@ void WebGLRenderingContextBase::compressedTexSubImage2D(GLenum target, GLint lev
 
 bool WebGLRenderingContextBase::validateSettableTexFormat(const char* functionName, GLenum format)
 {
-    if (WebGLImageConversion::getClearBitsByFormat(format) & (GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT)) {
+    if (WebGLImageConversion::getChannelBitsByFormat(format) & WebGLImageConversion::ChannelDepthStencil) {
         synthesizeGLError(GL_INVALID_OPERATION, functionName, "format can not be set, only rendered to");
         return false;
     }