Revert of Include class relationship diagrams in network stack documentation.

net/net.gyp

Index: net/net.gyp
diff --git a/net/net.gyp b/net/net.gyp
index 8c51208c1573d4141ac0286b108dd9bdd5351f51..1f30e79cc32e34d5004e56361dccc67e88b19ac6 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -706,6 +706,34 @@
       ],
     },
     {
+      'target_name': 'net_docs',
+      'type': 'none',
+      'actions': [
+        {
+          'action_name': 'net_docs',
+          'variables': {
+            'net_docs_input_dir': '.',
+          },
+          'inputs': [
+            '<@(net_docs_sources)',
+          ],
+          'outputs': [
+            '<(net_docs_output_dir)',
+          ],
+          'action': [
+            'python',
+            '<(net_docs_script)',
+            '--input_path',
+            '<(net_docs_input_dir)',
+            '--output_path',
+            '<(net_docs_output_dir)',
+            '<@(net_docs_sources)',
+          ],
+          'message': 'Rendering network stack documentation',
+        }
+      ],
+    },
+    {
       'target_name': 'http_server',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },