Post-commit review fixes after r242570

Fix remaining nits.

BUG=323697

Review URL: https://codereview.chromium.org/125253006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243346 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/android/content_video_view.h

@@ -31,7 +31,7 @@ class ContentVideoView {
       const base::android::ScopedJavaLocalRef<jobject>& client,
       BrowserMediaPlayerManager* manager);
 
-  ContentVideoView(BrowserMediaPlayerManager* manager);
+  explicit ContentVideoView(BrowserMediaPlayerManager* manager);
 
   ~ContentVideoView();