Allow "internal" APIs to be specified in extension API schemas.

chrome/common/extensions/docs/static/samples.html

Index: chrome/common/extensions/docs/static/samples.html
diff --git a/chrome/common/extensions/docs/static/samples.html b/chrome/common/extensions/docs/static/samples.html
index 0ae778c5ea9e32e72dbcfc0975f887e400d0e0da..2cd56a3ab9f43e61b437b00159c2d27c816e02f3 100644
--- a/chrome/common/extensions/docs/static/samples.html
+++ b/chrome/common/extensions/docs/static/samples.html
@@ -14,10 +14,9 @@
   pageData.api_mapping = apiMapping;
   pageData.api_modules = [];
   schema.forEach(function(mod) {
-    if (mod.nodoc) {
-      return;
-    }
-    if (mod.namespace.indexOf('experimental') != -1) {
+    if (mod.nodoc ||
+        mod.internal ||
+        mod.namespace.indexOf('experimental') != -1) {
       return;
     }
     pageData.api_modules.push('chrome.' + mod.namespace);