Refactor CpuProfiler.

src/log.h

Index: src/log.h
diff --git a/src/log.h b/src/log.h
index 2e222d4ebf07b82636d41060384433914f2420ba..358f38b6de3ae674514427618795f74d8e4b9cba 100644
--- a/src/log.h
+++ b/src/log.h
@@ -66,6 +66,7 @@ class Isolate;
 class Log;
 class PositionsRecorder;
 class Profiler;
+class ProfilerListener;
 class Ticker;
 struct TickSample;
 class RuntimeCallTimer;
@@ -167,6 +168,8 @@ class Logger {
 
   sampler::Sampler* sampler();
 
+  ProfilerListener* profiler_listener() { return profiler_listener_; }
+
   // Frees resources acquired in SetUp.
   // When a temporary file is used for the log, returns its stream descriptor,
   // leaving the file open.
@@ -394,6 +397,7 @@ class Logger {
   PerfJitLogger* perf_jit_logger_;
   LowLevelLogger* ll_logger_;
   JitLogger* jit_logger_;
+  ProfilerListener* profiler_listener_;
   List<CodeEventListener*> listeners_;
 
   // Guards against multiple calls to TearDown() that can happen in some tests.