Revert r15361 "Improved function entry hook coverage" because of ARM build error.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 981f81ce381ec50b90d14c5e843b9522048f20ea..e6f41691d0aab81d9faacc67b23bc0622342df96 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -547,7 +547,7 @@ class Isolate {
   }
   Context** context_address() { return &thread_local_top_.context_; }
 
-  SaveContext* save_context() { return thread_local_top_.save_context_; }
+  SaveContext* save_context() {return thread_local_top_.save_context_; }
   void set_save_context(SaveContext* save) {
     thread_local_top_.save_context_ = save;
   }
@@ -1050,8 +1050,6 @@ class Isolate {
     context_exit_happened_ = context_exit_happened;
   }
 
-  bool initialized_from_snapshot() { return initialized_from_snapshot_; }
-
   double time_millis_since_init() {
     return OS::TimeCurrentMillis() - time_millis_at_init_;
   }
@@ -1111,11 +1109,6 @@ class Isolate {
   HStatistics* GetHStatistics();
   HTracer* GetHTracer();
 
-  FunctionEntryHook function_entry_hook() { return function_entry_hook_; }
-  void set_function_entry_hook(FunctionEntryHook function_entry_hook) {
-    function_entry_hook_ = function_entry_hook;
-  }
-
  private:
   Isolate();
 
@@ -1295,9 +1288,6 @@ class Isolate {
   // that a context was recently exited.
   bool context_exit_happened_;
 
-  // True if this isolate was initialized from a snapshot.
-  bool initialized_from_snapshot_;
-
   // Time stamp at initialization.
   double time_millis_at_init_;
 
@@ -1321,7 +1311,6 @@ class Isolate {
 #endif
   CpuProfiler* cpu_profiler_;
   HeapProfiler* heap_profiler_;
-  FunctionEntryHook function_entry_hook_;
 
 #define GLOBAL_BACKING_STORE(type, name, initialvalue)                         \
   type name##_;