[scheduler] Move TimeBudgetPool to a separate file.

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc

Index: third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
index e7abd615da970ff376402809fb6e33d56917e641..36cfafc1a6b11cb53c79badaa5067b51122bb9cc 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
@@ -18,6 +18,7 @@
 #include "platform/scheduler/child/scheduler_tqm_delegate_for_test.h"
 #include "platform/scheduler/child/scheduler_tqm_delegate_impl.h"
 #include "platform/scheduler/renderer/auto_advancing_virtual_time_domain.h"
+#include "platform/scheduler/renderer/budget_pool.h"
 #include "platform/scheduler/renderer/web_frame_scheduler_impl.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -3697,7 +3698,7 @@ TEST_F(RendererSchedulerImplTest, Tracing) {
       new WebViewSchedulerImpl(nullptr, nullptr, scheduler_.get(), false));
   scheduler_->AddWebViewScheduler(web_view_scheduler2.get());
 
-  TaskQueueThrottler::TimeBudgetPool* time_budget_pool =
+  TimeBudgetPool* time_budget_pool =
       scheduler_->task_queue_throttler()->CreateTimeBudgetPool(
           "test", base::nullopt, base::nullopt);