Try to reduce the flankness of the PPAPI UI tests.

ppapi/tests/testing_instance.h

 // Copyright (c) 2011 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 PPAPI_TESTS_TESTING_INSTANCE_H_
 #define PPAPI_TESTS_TESTING_INSTANCE_H_
 
 #include <string>
 
 #include "ppapi/cpp/completion_callback.h"
 
 #if defined(__native_client__)
 #include "ppapi/cpp/instance.h"
 #else
 #include "ppapi/cpp/private/instance_private.h"
 #endif
 
 class TestCase;
 
+// How signaling works:
+//
+// We want to signal to the Chrome UI test harness
+// (chrome/test/ui/ppapi_uitest.cc) that we're making progress and when we're
+// done. The easiest thing in the UI test infrastructure is to wait for a
+// cookie to become nonempty. We don't want to have a big wait for all tests in
+// a TestCase since they can take a while and it might timeout.  So we set a
+// series of cookies with an incrementing number in the name.
+//
+// If the value of the cookie is "..." then that tells the test runner that
+// the test is progressing. It then waits for the next numbered cookie until
+// it either times out or the value is something other than "...". In this
+// case, the value will be either "PASS" or "FAIL [optional message]"
+// corresponding to the outcome of the entire test case. Timeout will be
+// treated just like a failure of the entire test case and the test will be
+// terminated.
+//
 // In trusted builds, we use InstancePrivate and allow tests that use
 // synchronous scripting. NaCl does not support synchronous scripting.
 class TestingInstance : public
 #if defined(__native_client__)
 pp::Instance {
 #else
 pp::InstancePrivate {
 #endif
  public:
   explicit TestingInstance(PP_Instance instance);
@@ skipping 44 matching lines @@
 
   // Appends a list of available tests to the console in the document.
   void LogAvailableTests();
 
   // Appends the given error test to the console in the document.
   void LogError(const std::string& text);
 
   // Appends the given HTML string to the console in the document.
   void LogHTML(const std::string& html);
 
+  void ReportProgress(const std::string& progress_value);
+
   // Sets the given cookie in the current document.
   void SetCookie(const std::string& name, const std::string& value);
 
   pp::CompletionCallbackFactory<TestingInstance> callback_factory_;
 
   // Owning pointer to the current test case. Valid after Init has been called.
   TestCase* current_case_;
 
+  // The current step we're on starting at 0. This is incremented every time we
+  // report progress via a cookie. See comment above the class.
+  int progress_cookie_number_;
+
   // Set once the tests are run so we know not to re-run when the view is sized.
   bool executed_tests_;
 
   // Collects all errors to send the the browser. Empty indicates no error yet.
   std::string errors_;
 
   // True if running in Native Client.
   bool nacl_mode_;
 
   // String representing the protocol.  Used for detecting whether we're running
   // with http.
   std::string protocol_;
 };
 
 #endif  // PPAPI_TESTS_TESTING_INSTANCE_H_