Simplify ProfLazyMode test on Linux.

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index d12aafb6df87e59c877d7ff775c8f05a57d59cf5..55f15debd04e145c34762271854150faef99f121 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -194,11 +194,6 @@ class Ticker: public Sampler {
 
   ~Ticker() { if (IsActive()) Stop(); }
 
-  virtual void SampleStack(TickSample* sample) {
-    ASSERT(IsSynchronous());
-    StackTracer::Trace(sample);
-  }
-
   virtual void Tick(TickSample* sample) {
     if (profiler_) profiler_->Insert(sample);
     if (window_) window_->AddState(sample->state);
@@ -224,6 +219,12 @@ class Ticker: public Sampler {
     if (!window_ && IsActive()) Stop();
   }
 
+ protected:
+  virtual void DoSampleStack(TickSample* sample) {
+    ASSERT(IsSynchronous());
+    StackTracer::Trace(sample);
+  }
+
  private:
   SlidingStateWindow* window_;
   Profiler* profiler_;