[OfflinePages] Improve visiblity/handling of "Loading not started" case

chrome/browser/android/offline_pages/prerendering_offliner_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/offline_pages/prerendering_offliner.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/run_loop.h"
@@ skipping 25 matching lines @@
 class MockPrerenderingLoader : public PrerenderingLoader {
  public:
   explicit MockPrerenderingLoader(content::BrowserContext* browser_context)
       : PrerenderingLoader(browser_context),
         can_prerender_(true),
         mock_loading_(false),
         mock_loaded_(false) {}
   ~MockPrerenderingLoader() override {}
 
   bool LoadPage(const GURL& url, const LoadPageCallback& callback) override {
-    mock_loading_ = true;
+    mock_loading_ = can_prerender_;
     load_page_callback_ = callback;
     return mock_loading_;
   }
 
   void StopLoading() override {
     mock_loading_ = false;
     mock_loaded_ = false;
   }
 
-  bool CanPrerender() override { return can_prerender_; }
   bool IsIdle() override { return !mock_loading_ && !mock_loaded_; }
   bool IsLoaded() override { return mock_loaded_; }
 
   void CompleteLoadingAsFailed() {
     DCHECK(mock_loading_);
     mock_loading_ = false;
     mock_loaded_ = false;
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE,
         base::Bind(load_page_callback_, Offliner::RequestStatus::LOADING_FAILED,
@@ skipping 327 matching lines @@
   EXPECT_FALSE(loader()->IsIdle());
 
   offliner()->SetApplicationStateForTesting(
       base::android::APPLICATION_STATE_HAS_RUNNING_ACTIVITIES);
 
   // Loader still loading since not low-end device.
   EXPECT_FALSE(loader()->IsIdle());
 }
 
 }  // namespace offline_pages