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

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index dab3688bd96470b894eb066b066613809fd3900c..6b6ba79b44680eb3a2e5e1636053743845ff44a5 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -2135,6 +2135,13 @@ class ProfileEntryHookStub : public PlatformCodeStub {
   // Generates a call to the entry hook if it's enabled.
   static void MaybeCallEntryHook(MacroAssembler* masm);
 
+  // Sets or unsets the entry hook function. Returns true on success,
+  // false on an attempt to replace a non-NULL entry hook with another
+  // non-NULL hook.
+  static bool SetFunctionEntryHook(FunctionEntryHook entry_hook);
+
+  static bool HasEntryHook() { return entry_hook_ != NULL; }
+
  private:
   static void EntryHookTrampoline(intptr_t function,
                                   intptr_t stack_pointer);
@@ -2144,6 +2151,9 @@ class ProfileEntryHookStub : public PlatformCodeStub {
 
   void Generate(MacroAssembler* masm);
 
+  // The current function entry hook.
+  static FunctionEntryHook entry_hook_;
+
   DISALLOW_COPY_AND_ASSIGN(ProfileEntryHookStub);
 };