Move renderer plugin code into a new component.

chrome/chrome_renderer.gypi

Index: chrome/chrome_renderer.gypi
diff --git a/chrome/chrome_renderer.gypi b/chrome/chrome_renderer.gypi
index a4949ee7880ae6184d6d76ff0ab92a1568348860..e67b0e5d56ecbbaa80556967d452b2fce8b8115d 100644
--- a/chrome/chrome_renderer.gypi
+++ b/chrome/chrome_renderer.gypi
@@ -15,6 +15,7 @@
         'chrome_resources.gyp:chrome_strings',
         '../components/components.gyp:autofill_content_renderer',
         '../components/components.gyp:startup_metric_utils',
+        '../components/components.gyp:plugins_renderer',
         '../components/components.gyp:visitedlink_renderer',
         '../content/content.gyp:content_renderer',
         '../net/net.gyp:net',
@@ -263,12 +264,8 @@
         'renderer/pepper/ppb_nacl_private_impl.h',
         'renderer/pepper/ppb_pdf_impl.cc',
         'renderer/pepper/ppb_pdf_impl.h',
-        'renderer/plugins/plugin_placeholder.cc',
-        'renderer/plugins/plugin_placeholder.h',
-        'renderer/plugins/plugin_uma.cc',
-        'renderer/plugins/plugin_uma.h',
-        'renderer/plugins/webview_plugin.cc',
-        'renderer/plugins/webview_plugin.h',
+        'renderer/plugins/chrome_plugin_placeholder.cc',
+        'renderer/plugins/chrome_plugin_placeholder.h',
         'renderer/prerender/prerender_dispatcher.cc',
         'renderer/prerender/prerender_dispatcher.h',
         'renderer/prerender/prerender_extra_data.cc',