Plugin Power Saver: Replace all "plug-in" with "plugin" for consistency.

chrome/browser/plugins/plugin_metadata.cc

Index: chrome/browser/plugins/plugin_metadata.cc
diff --git a/chrome/browser/plugins/plugin_metadata.cc b/chrome/browser/plugins/plugin_metadata.cc
index 33f83a029688fdfc5c5133f03e029a39ddf78641..e79df9e550c711c2199511144d7f29c31250eda3 100644
--- a/chrome/browser/plugins/plugin_metadata.cc
+++ b/chrome/browser/plugins/plugin_metadata.cc
@@ -61,7 +61,7 @@ bool PluginMetadata::HasMimeType(const std::string& mime_type) const {
 bool PluginMetadata::MatchesPlugin(const content::WebPluginInfo& plugin) {
   for (size_t i = 0; i < matching_mime_types_.size(); ++i) {
     // To have a match, every one of the |matching_mime_types_|
-    // must be handled by the plug-in.
+    // must be handled by the plugin.
     size_t j = 0;
     for (; j < plugin.mime_types.size(); ++j) {
       if (plugin.mime_types[j].mime_type == matching_mime_types_[i])