Fix building with profilingsupport=off

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 0474ce0c5ad7e996e797aec02da2c3b29111eb5d..298ef6eea70e3c2533ff928833602cfa6fa0f124 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -1878,7 +1878,11 @@ bool Logger::Setup() {
 
 
 Sampler* Logger::sampler() {
+#ifdef ENABLE_LOGGING_AND_PROFILING
   return ticker_;
+#else
+  return NULL;
+#endif
 }
 
 
@@ -1955,8 +1959,10 @@ bool SamplerRegistry::IterateActiveSamplers(VisitSampler func, void* param) {
 
 
 static void ComputeCpuProfiling(Sampler* sampler, void* flag_ptr) {
+#ifdef ENABLE_LOGGING_AND_PROFILING
   bool* flag = reinterpret_cast<bool*>(flag_ptr);
   *flag |= sampler->IsProfiling();
+#endif
 }