Adds unit tests for Offliner SavePage implementation.

chrome/browser/android/offline_pages/prerendering_offliner.cc

Index: chrome/browser/android/offline_pages/prerendering_offliner.cc
diff --git a/chrome/browser/android/offline_pages/prerendering_offliner.cc b/chrome/browser/android/offline_pages/prerendering_offliner.cc
index d873b02238b9a17c4a0767c5a36af87a1fa09a74..fb89eae1f12e66e2303fe12624c4b2f6f1f79440 100644
--- a/chrome/browser/android/offline_pages/prerendering_offliner.cc
+++ b/chrome/browser/android/offline_pages/prerendering_offliner.cc
@@ -101,8 +101,13 @@ bool PrerenderingOffliner::LoadAndSave(const SavePageRequest& request,
     return false;
   }
 
-  if (!CanSavePage(request.url())) {
-    DVLOG(1) << "Not able to save page";
+  if (!GetOrCreateLoader()->CanPrerender()) {
+    DVLOG(1) << "Prerendering not allowed/configured";
+    return false;
+  }
+
+  if (!OfflinePageModel::CanSavePage(request.url())) {
+    DVLOG(1) << "Not able to save page for requested url: " << request.url();
     return false;
   }
 
@@ -134,15 +139,6 @@ void PrerenderingOffliner::SetLoaderForTesting(
   loader_ = std::move(loader);
 }
 
-bool PrerenderingOffliner::CanSavePage(const GURL& url) {
-  if (!offline_page_model_) {
-    // Assume we can save if no OfflinePageModel (for unit tests).
-    // TODO(dougarnett): Make OfflinePageModel::CanSavePage() mockable for test.
-    return true;
-  }
-  return offline_page_model_->CanSavePage(url);
-}
-
 void PrerenderingOffliner::SavePage(
     const GURL& url,
     const ClientId& client_id,