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 0cd98f6b376455e9704cdcd207c4bbf0f8d0f9e8..b63a772076050ae7dcfb466345d221e40a86672a 100644
--- a/Source/core/html/canvas/WebGLRenderingContextBase.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
@@ -1532,7 +1532,7 @@ 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;
     }