One Zone per CompilationInfo.

src/compiler.h

Index: src/compiler.h
diff --git a/src/compiler.h b/src/compiler.h
index 44df9e090f1e17b4ac7ef59eb1356c8b2e0cde32..5bea4d0fdbecbe11cf06c78120e7cd20296bfefd 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -41,14 +41,17 @@ class ScriptDataImpl;
 // is constructed based on the resources available at compile-time.
 class CompilationInfo BASE_EMBEDDED {
  public:
-  explicit CompilationInfo(Handle<Script> script);
-  explicit CompilationInfo(Handle<SharedFunctionInfo> shared_info);
-  explicit CompilationInfo(Handle<JSFunction> closure);
+  CompilationInfo(Handle<Script> script, Zone* zone);
+  CompilationInfo(Handle<SharedFunctionInfo> shared_info, Zone* zone);
+  CompilationInfo(Handle<JSFunction> closure, Zone* zone);
 
   Isolate* isolate() {
     ASSERT(Isolate::Current() == isolate_);
     return isolate_;
   }
+  Zone* zone() {
+    return zone_;
+  }
   bool is_lazy() const { return IsLazy::decode(flags_); }
   bool is_eval() const { return IsEval::decode(flags_); }
   bool is_global() const { return IsGlobal::decode(flags_); }
@@ -184,8 +187,6 @@ class CompilationInfo BASE_EMBEDDED {
     NONOPT
   };
 
-  CompilationInfo() : function_(NULL) {}
-
   void Initialize(Mode mode) {
     mode_ = V8::UseCrankshaft() ? mode : NONOPT;
     ASSERT(!script_.is_null());
@@ -254,6 +255,10 @@ class CompilationInfo BASE_EMBEDDED {
   Mode mode_;
   int osr_ast_id_;
 
+  // The zone from which the compilation pipeline working on this
+  // CompilationInfo allocates.
+  Zone* zone_;
+
   DISALLOW_COPY_AND_ASSIGN(CompilationInfo);
 };