weblayer: update doc of Navigation.setRequestHeader()

onNavigationStarted() was mentioned twice. The second should
be onNavigationRedirected.

BUG=none
TEST=comment only change

Change-Id: I0a6b23a1877256ab09532d4adc8c105345a89a02
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2323708
Commit-Queue: Scott Violet <sky@chromium.org>
Commit-Queue: Clark DuVall <cduvall@chromium.org>
Auto-Submit: Scott Violet <sky@chromium.org>
Reviewed-by: Clark DuVall <cduvall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792294}

weblayer/public/java/org/chromium/weblayer/Navigation.java

@@ -169,8 +169,8 @@ public class Navigation extends IClientNavigation.Stub {
      * Sets a header for a network request. If a header with the specified name exists it is
      * overwritten. This method can only be called at two times, from
      * {@link NavigationCallback.onNavigationStarted} and {@link
-     * NavigationCallback.onNavigationStarted}. When called during start, the header applies to both
-     * the initial network request as well as redirects.
+     * NavigationCallback.onNavigationRedirected}. When called during start, the header applies to
+     * both the initial network request as well as redirects.
      *
      * @param name The name of the header. The name must be rfc 2616 compliant.
      * @param value The value of the header. The value must not contain '\0', '\n' or '\r'.