Represent speed in GCTracer functions as double instead of int.

src/heap/incremental-marking.cc

 // Copyright 2012 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.
 
 #include "src/heap/incremental-marking.h"
 
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/conversions.h"
 #include "src/heap/gc-idle-time-handler.h"
@@ skipping 1006 matching lines @@
 }
 
 
 double IncrementalMarking::AdvanceIncrementalMarking(
     intptr_t step_size_in_bytes, double deadline_in_ms,
     IncrementalMarking::StepActions step_actions) {
   DCHECK(!IsStopped());
 
   if (step_size_in_bytes == 0) {
     step_size_in_bytes = GCIdleTimeHandler::EstimateMarkingStepSize(
-        static_cast<size_t>(GCIdleTimeHandler::kIncrementalMarkingStepTimeInMs),
-        static_cast<size_t>(
-            heap()
-                ->tracer()
-                ->FinalIncrementalMarkCompactSpeedInBytesPerMillisecond()));
+        GCIdleTimeHandler::kIncrementalMarkingStepTimeInMs,
+        heap()
+            ->tracer()
+            ->FinalIncrementalMarkCompactSpeedInBytesPerMillisecond());
   }
 
   double remaining_time_in_ms = 0.0;
   do {
     Step(step_size_in_bytes, step_actions.completion_action,
          step_actions.force_marking, step_actions.force_completion);
     remaining_time_in_ms =
         deadline_in_ms - heap()->MonotonicallyIncreasingTimeInMs();
   } while (remaining_time_in_ms >=
                2.0 * GCIdleTimeHandler::kIncrementalMarkingStepTimeInMs &&
@@ skipping 204 matching lines @@
 void IncrementalMarking::IncrementIdleMarkingDelayCounter() {
   idle_marking_delay_counter_++;
 }
 
 
 void IncrementalMarking::ClearIdleMarkingDelayCounter() {
   idle_marking_delay_counter_ = 0;
 }
 }  // namespace internal
 }  // namespace v8