Add support for idle tasks to the default platform

include/libplatform/libplatform.h

 // Copyright 2014 the V8 project 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 V8_LIBPLATFORM_LIBPLATFORM_H_
 #define V8_LIBPLATFORM_LIBPLATFORM_H_
 
 #include "libplatform/libplatform-export.h"
 #include "libplatform/v8-tracing.h"
 #include "v8-platform.h"  // NOLINT(build/include)
@@ skipping 17 matching lines @@
  *
  * The caller has to make sure that this is called from the right thread.
  * Returns true if a task was executed, and false otherwise. This call does
  * not block if no task is pending. The |platform| has to be created using
  * |CreateDefaultPlatform|.
  */
 V8_PLATFORM_EXPORT bool PumpMessageLoop(v8::Platform* platform,
                                         v8::Isolate* isolate);
 
 /**
+ * Runs pending idle tasks for at most |idle_time_in_seconds| seconds.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * This call does not block if no task is pending. The |platform| has to be
+ * created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void RunIdleTasks(v8::Platform* platform,
+                                     v8::Isolate* isolate,
+                                     double idle_time_in_seconds);
+
+/**
  * Attempts to set the tracing controller for the given platform.
  *
  * The |platform| has to be created using |CreateDefaultPlatform|.
  */
 V8_PLATFORM_EXPORT void SetTracingController(
     v8::Platform* platform,
     v8::platform::tracing::TracingController* tracing_controller);
 
 }  // namespace platform
 }  // namespace v8
 
 #endif  // V8_LIBPLATFORM_LIBPLATFORM_H_