IsolatedPrerender Don't Ignore Same Document Navigations

This ensures that AMP pages (often same-doc navigations) get the same
treatment.

Bug: 1023485
Change-Id: Id300abd499696e87cc2261c205f9e7ea9c3a8d59
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2129015
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Auto-Submit: Robert Ogden <robertogden@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755027}

chrome/browser/prerender/isolated/isolated_prerender_tab_helper.cc

@@ -111,9 +111,6 @@ void IsolatedPrerenderTabHelper::DidStartNavigation(
   if (!navigation_handle->IsInMainFrame()) {
     return;
   }
-  if (navigation_handle->IsSameDocument()) {
-    return;
-  }
 
   // User is navigating, don't bother prefetching further.
   page_->url_loader_.reset();
@@ -125,9 +122,6 @@ void IsolatedPrerenderTabHelper::DidFinishNavigation(
   if (!navigation_handle->IsInMainFrame()) {
     return;
   }
-  if (navigation_handle->IsSameDocument()) {
-    return;
-  }
   if (!navigation_handle->HasCommitted()) {
     return;
   }