Clean up plug-in placeholders:

chrome/chrome_renderer.gypi

Index: chrome/chrome_renderer.gypi
diff --git a/chrome/chrome_renderer.gypi b/chrome/chrome_renderer.gypi
index de71c77f537d707fb85c80c8cffbbd15c20b4c47..fcb5e8bd717f34a174a9dfa6e5572af02c8e493b 100644
--- a/chrome/chrome_renderer.gypi
+++ b/chrome/chrome_renderer.gypi
@@ -109,8 +109,6 @@
         'renderer/resources/extensions/schema_generated_bindings.js',
         'renderer/about_handler.cc',
         'renderer/about_handler.h',
-        'renderer/blocked_plugin.cc',
-        'renderer/blocked_plugin.h',
         'renderer/chrome_content_renderer_client.cc',
         'renderer/chrome_content_renderer_client.h',
         'renderer/chrome_ppapi_interfaces.cc',
@@ -123,6 +121,7 @@
         'renderer/chrome_render_view_observer.h',
         'renderer/content_settings_observer.cc',
         'renderer/content_settings_observer.h',
+        'renderer/custom_menu_commands.h',
         'renderer/external_host_bindings.cc',
         'renderer/external_host_bindings.h',
         'renderer/external_extension.cc',
@@ -134,8 +133,14 @@
         'renderer/page_click_tracker.h',
         'renderer/page_load_histograms.cc',
         'renderer/page_load_histograms.h',
-        'renderer/plugin_uma.cc',
-        'renderer/plugin_uma.h',
+        'renderer/plugins/blocked_plugin.cc',
+        'renderer/plugins/blocked_plugin.h',
+        'renderer/plugins/missing_plugin.cc',
+        'renderer/plugins/missing_plugin.h',
+        'renderer/plugins/plugin_placeholder.cc',
+        'renderer/plugins/plugin_placeholder.h',
+        'renderer/plugins/plugin_uma.cc',
+        'renderer/plugins/plugin_uma.h',
         'renderer/prerender/prerender_helper.cc',
         'renderer/prerender/prerender_helper.h',
         'renderer/print_web_view_helper.cc',