Add back unseparated out version of method overloads in dart:html.

tools/dom/docs/docs.json

 {
   "dart.dom.html": {
     "CanvasGradient": {
       "comment": [
         "/**",
         " * An opaque canvas object representing a gradient.",
         " *",
         " * Created by calling [createLinearGradient] or [createRadialGradient] on a",
         " * [CanvasRenderingContext2D] object.",
         " *",
@@ skipping 511 matching lines @@
           "   * Get a Stream that fires events when AudioProcessingEvents occur.",
           "   * This particular stream is special in that it only allows one listener to a",
           "   * given stream. Converting the returned Stream [asBroadcast] will likely ruin",
           "   * the soft-real-time properties which which these events are fired and can",
           "   * be processed.",
           "   */"
         ]
       }
     }
   },
+  "dart.dom.web_gl": {
+    "WebGLRenderingContext": {
+      "members": {
+        "bufferData": [
+          "/**",
+          "   * Buffers the specified data.",
+          "   *",
+          "   * This specific method is provided for WebGL API compatibility reasons, but",
+          "   * it is highly recommended that you use [bufferDataTyped] or [bufferByteData]",
+          "   * depending on your purposes.",
+          "   */"
+        ],
+        "bufferSubData": [
+          "/**",
+          "   * Buffers the specified subset of data.",
+          "   *",
+          "   * This specific method is provided for WebGL API compatibility reasons, but",
+          "   * it is highly recommended that you use [bufferSubDataTyped] or [bufferSubByteData]",
+          "   * depending on your purposes.",
+          "   */"
+        ],
+        "texImage2D": [
+          "/**",
+          "   * Updates the currently bound texture to [data].",
+          "   *",
+          "   * This specific method is provided for WebGL API compatibility reasons, but it",
+          "   * is highly recommended that you use [texImage2DUntyped] or [texImage2DTyped]",
+          "   * (or for more specificity, the more specialized [texImage2DImageData],",
+          "   * [texImage2DCanvas], [texImage2DVideo]).",
+          "   */"
+        ],
+        "texSubImage2D": [
+          "/**",
+          "   * Updates a sub-rectangle of the currently bound texture to [data].",
+          "   *",
+          "   * This specific method is provided for WebGL API compatibility reasons, but it",
+          "   * is highly recommended that you use [texSubImage2DUntyped] or [texSubImage2DTyped]",
+          "   * (or for more specificity, the more specialized [texSubImage2DImageData],",
+          "   * [texSubImage2DCanvas], [texSubImage2DVideo]).",
+          "   */"
+        ]
+      }
+    }
+  },
   "dart.dom.web_sql": {
     "Database": {
       "members": {
         "changeVersion": [
           "/**",
           "   * Atomically update the database version to [newVersion], asynchronously",
           "   * running [callback] on the [SqlTransaction] representing this",
           "   * [changeVersion] transaction.",
           "   *",
           "   * If [callback] runs successfully, then [successCallback] is called.",
           "   * Otherwise, [errorCallback] is called.",
           "   *",
           "   * [oldVersion] should match the database's current [version] exactly.",
           "   *",
           "   * * [Database.changeVersion](http://www.w3.org/TR/webdatabase/#dom-database-changeversion) from W3C.",
           "   */"
         ]
       }
     }
   }
 }