Re-applying r76324, which was reverted during a WebKit rollback.

chrome/browser/tab_contents/render_view_host_delegate_helper.cc

Index: chrome/browser/tab_contents/render_view_host_delegate_helper.cc
diff --git a/chrome/browser/tab_contents/render_view_host_delegate_helper.cc b/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
index 45351b989a81eceed88326749d8320f3af399f8f..e959775b86ca1c549af401407e9e2dbc534f3daf 100644
--- a/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
+++ b/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
@@ -305,6 +305,9 @@ WebPreferences RenderViewHostDelegateHelper::GetWebkitPrefs(
         !command_line.HasSwitch(switches::kNoPings);
     web_prefs.interactive_form_validation_enabled =
         !command_line.HasSwitch(switches::kDisableInteractiveFormValidation);
+    web_prefs.fullscreen_enabled =
+        command_line.HasSwitch(switches::kEnableFullScreen);
+
     // The user stylesheet watcher may not exist in a testing profile.
     if (profile->GetUserStyleSheetWatcher()) {
       web_prefs.user_style_sheet_enabled = true;