Remove the task tracking stuff in the bindings.

mojo/public/cpp/environment/environment.h

 // Copyright 2014 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 MOJO_PUBLIC_CPP_ENVIRONMENT_ENVIRONMENT_H_
 #define MOJO_PUBLIC_CPP_ENVIRONMENT_ENVIRONMENT_H_
 
 #include "mojo/public/cpp/system/macros.h"
 
 struct MojoAsyncWaiter;
 struct MojoLogger;
 
 namespace mojo {
 
-struct TaskTracker;
-
 // Other parts of the Mojo C++ APIs use the *static* methods of this class.
 //
 // The "standalone" implementation of this class requires that this class (in
 // the lib/ subdirectory) be instantiated (and remain so) while using the Mojo
 // C++ APIs. I.e., the static methods depend on things set up by the constructor
 // and torn down by the destructor.
 //
 // Other implementations may not have this requirement.
 class Environment {
  public:
   Environment();
   // This constructor allows the standard implementations to be overridden (set
   // a parameter to null to get the standard implementation).
   Environment(const MojoAsyncWaiter* default_async_waiter,
-              const MojoLogger* default_logger,
-              const TaskTracker* default_task_tracker);
+              const MojoLogger* default_logger);
   ~Environment();
 
   static const MojoAsyncWaiter* GetDefaultAsyncWaiter();
   static const MojoLogger* GetDefaultLogger();
-  static const TaskTracker* GetDefaultTaskTracker();
 
   // These instantiate and destroy an environment-specific run loop for the
   // current thread, allowing |GetDefaultAsyncWaiter()| to be used. (The run
   // loop itself should be accessible via thread-local storage, using methods
   // specific to the run loop implementation.) Creating and destroying nested
   // run loops is not supported.
   static void InstantiateDefaultRunLoop();
   static void DestroyDefaultRunLoop();
 
  private:
   MOJO_DISALLOW_COPY_AND_ASSIGN(Environment);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_ENVIRONMENT_ENVIRONMENT_H_