Replace "nested message loop" with "nested run loop" in comments.

content/public/test/test_frame_navigation_observer.h

Index: content/public/test/test_frame_navigation_observer.h
diff --git a/content/public/test/test_frame_navigation_observer.h b/content/public/test/test_frame_navigation_observer.h
index 928801e99b72c6b8910aa6681bf996bd713c2546..e6f0d3e4c76964dc28790518e76949d3197c9cf9 100644
--- a/content/public/test/test_frame_navigation_observer.h
+++ b/content/public/test/test_frame_navigation_observer.h
@@ -24,11 +24,11 @@ class TestFrameNavigationObserver : public WebContentsObserver {
 
   ~TestFrameNavigationObserver() override;
 
-  // Runs a nested message loop and blocks until the full load has
+  // Runs a nested run loop and blocks until the full load has
   // completed.
   void Wait();
 
-  // Runs a nested message loop and blocks until the navigation in the
+  // Runs a nested run loop and blocks until the navigation in the
   // associated FrameTreeNode has committed.
   void WaitForCommit();