Improving comment for WebLayer's PrepareForPossibleCrossOriginNavigation added in r797754.

Change-Id: I366c1c6040918d6905264ddaa62b340cbe06db2b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2355002
Auto-Submit: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Darin Fisher <darin@chromium.org>
Commit-Queue: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799519}

weblayer/public/java/org/chromium/weblayer/Profile.java

@@ -315,13 +315,13 @@ public class Profile {
     }
 
     /**
-     * If an embedder knows that a cross-origin navigation is likely starting soon they can call
-     * this method to start a spare renderer process. A subsequent navigation may use this
-     * preinitialized process, improving performance.
-     *
-     * It is safe to call this multiple times or when it is not certain that the spare renderer will
-     * be used, although calling this too eagerly may reduce performance as unnecessary processes
-     * are created.
+     * For cross-origin navigations, the implementation may leverage a separate OS process for
+     * stronger isolation. If an embedder knows that a cross-origin navigation is likely starting
+     * soon, they can call this method as a hint to the implementation to start a fresh OS process.
+     * A subsequent navigation may use this preinitialized process, improving performance. It is
+     * safe to call this multiple times or when it is not certain that the spare renderer will be
+     * used, although calling this too eagerly may reduce performance as unnecessary processes are
+     * created.
      *
      * @since 85
      */

weblayer/public/profile.h

@@ -103,13 +103,14 @@ class Profile {
       const GURL& page_url,
       base::OnceCallback<void(gfx::Image)> callback) = 0;
 
-  // If an embedder knows that a cross-origin navigation is likely starting soon
-  // they can call this method to start a spare renderer process. A subsequent
-  // navigation may use this preinitialized process, improving performance.
-
-  // It is safe to call this multiple times or when it is not certain that the
-  // spare renderer will be used, although calling this too eagerly may reduce
-  // performance as unnecessary processes are created.
+  // For cross-origin navigations, the implementation may leverage a separate OS
+  // process for stronger isolation. If an embedder knows that a cross-origin
+  // navigation is likely starting soon, they can call this method as a hint to
+  // the implementation to start a fresh OS process. A subsequent navigation may
+  // use this preinitialized process, improving performance. It is safe to call
+  // this multiple times or when it is not certain that the spare renderer will
+  // be used, although calling this too eagerly may reduce performance as
+  // unnecessary processes are created.
   virtual void PrepareForPossibleCrossOriginNavigation() = 0;
 };