Prerender: remove possible race in browser tests to improve flakiness.

chrome/browser/prerender/prerender_test_utils.h

 // Copyright (c) 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.
 
 #ifndef CHROME_BROWSER_PRERENDER_PRERENDER_TEST_UTILS_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_TEST_UTILS_H_
 
 #include <functional>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 135 matching lines @@
 // tracking the final status, etc.
 class TestPrerender : public PrerenderContents::Observer,
                       public base::SupportsWeakPtr<TestPrerender> {
  public:
   TestPrerender();
   ~TestPrerender() override;
 
   TestPrerenderContents* contents() const { return contents_; }
   int number_of_loads() const { return number_of_loads_; }
 
-  void WaitForCreate() { create_loop_.Run(); }
-  void WaitForStart() { start_loop_.Run(); }
-  void WaitForStop() { stop_loop_.Run(); }
+  void WaitForCreate();
+  void WaitForStart();
+  void WaitForStop();
 
   // Waits for |number_of_loads()| to be at least |expected_number_of_loads| OR
   // for the prerender to stop running (just to avoid a timeout if the prerender
   // dies). Note: this does not assert equality on the number of loads; the
   // caller must do it instead.
   void WaitForLoads(int expected_number_of_loads);
 
   void OnPrerenderCreated(TestPrerenderContents* contents);
 
   // PrerenderContents::Observer implementation:
   void OnPrerenderStart(PrerenderContents* contents) override;
 
   void OnPrerenderStopLoading(PrerenderContents* contents) override;
 
   void OnPrerenderStop(PrerenderContents* contents) override;
 
  private:
   TestPrerenderContents* contents_;
   int number_of_loads_;
 
   int expected_number_of_loads_;
   std::unique_ptr<base::RunLoop> load_waiter_;
 
+  bool started_;
+  bool stopped_;
+
   base::RunLoop create_loop_;
   base::RunLoop start_loop_;
   base::RunLoop stop_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(TestPrerender);
 };
 
 // Blocks until a TestPrerenderContents has been destroyed with the given final
 // status. Should be created with a TestPrerenderContents, and then
 // WaitForDestroy should be called and its return value checked.
@@ skipping 182 matching lines @@
     const base::WeakPtr<RequestCounter>& counter);
 
 // Makes |url| respond to requests with the contents of |file|.
 void CreateMockInterceptorOnIO(const GURL& url, const base::FilePath& file);
 
 }  // namespace test_utils
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_TEST_UTILS_H_