Simplify sampling rate calculation

test/cctest/test-cpu-profiler.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 204 matching lines @@
       frame2_code->instruction_start() + frame2_code->ExecutableSize() / 2,
       frame1_code->instruction_start() + frame2_code->ExecutableSize() / 2);
   EnqueueTickSampleEvent(
       &processor,
       frame3_code->instruction_end() - 1,
       frame2_code->instruction_end() - 1,
       frame1_code->instruction_end() - 1);
 
   processor.StopSynchronously();
   processor.Join();
-  CpuProfile* profile = profiles->StopProfiling("", 1);
+  CpuProfile* profile = profiles->StopProfiling("");
   CHECK_NE(NULL, profile);
 
   // Check call trees.
   const i::List<ProfileNode*>* top_down_root_children =
       profile->top_down()->root()->children();
   CHECK_EQ(1, top_down_root_children->length());
   CHECK_EQ("bbb", top_down_root_children->last()->entry()->name());
   const i::List<ProfileNode*>* top_down_bbb_children =
       top_down_root_children->last()->children();
   CHECK_EQ(1, top_down_bbb_children->length());
@@ skipping 43 matching lines @@
   i::TickSample* sample = processor.TickSampleEvent();
   sample->pc = code->address();
   sample->tos = 0;
   sample->frames_count = i::TickSample::kMaxFramesCount;
   for (int i = 0; i < sample->frames_count; ++i) {
     sample->stack[i] = code->address();
   }
 
   processor.StopSynchronously();
   processor.Join();
-  CpuProfile* profile = profiles->StopProfiling("", 1);
+  CpuProfile* profile = profiles->StopProfiling("");
   CHECK_NE(NULL, profile);
 
   int actual_depth = 0;
   const ProfileNode* node = profile->top_down()->root();
   while (node->children()->length() > 0) {
     node = node->children()->last();
     ++actual_depth;
   }
 
   CHECK_EQ(1 + i::TickSample::kMaxFramesCount, actual_depth);  // +1 for PC.
@@ skipping 1002 matching lines @@
 
   CHECK_EQ(1, barNode->GetChildrenCount());
   const v8::CpuProfileNode* nativeNode2 = GetChild(barNode, "CallJsFunction2");
 
   CHECK_EQ(1, nativeNode2->GetChildrenCount());
   GetChild(nativeNode2, "foo");
 
   v8::CpuProfiler* cpu_profiler = env->GetIsolate()->GetCpuProfiler();
   cpu_profiler->DeleteAllCpuProfiles();
 }