Fix texImage2D on Dartium.

tools/dom/templates/html/impl/impl_WebGLRenderingContext.darttemplate

Index: tools/dom/templates/html/impl/impl_WebGLRenderingContext.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_WebGLRenderingContext.darttemplate b/tools/dom/templates/html/impl/impl_WebGLRenderingContext.darttemplate
index 893d9df418be255ec7a95cba46e1a8282a7d702e..3b233f34c10c2cd02aff7d7073206263c875712e 100644
--- a/tools/dom/templates/html/impl/impl_WebGLRenderingContext.darttemplate
+++ b/tools/dom/templates/html/impl/impl_WebGLRenderingContext.darttemplate
@@ -24,8 +24,19 @@ $if DART2JS
 $else
   void texImage2D(int targetTexture, int levelOfDetail, int internalFormat,
       int format, int type, data) {
-    _texImage2D(targetTexture, levelOfDetail, internalFormat,
-        format, type, data);
+    if (data is ImageElement) {
+      texImage2DImage(targetTexture, levelOfDetail, internalFormat, format,
+          type, data);
+    } else if (data is ImageData) {
+      texImage2DImageData(targetTexture, levelOfDetail, internalFormat, format,
+          type, data);
+    } else if (data is CanvasElement) {
+      texImage2DCanvas(targetTexture, levelOfDetail, internalFormat, format,
+          type, data);
+    } else {
+      texImage2DVideo(targetTexture, levelOfDetail, internalFormat, format,
+          type, data);
+    }
   }
 $endif