Replaced empty handle checks with MaybeHandles

src/jsregexp.cc

Index: src/jsregexp.cc
diff --git a/src/jsregexp.cc b/src/jsregexp.cc
index 5fa6cf49d7750689ece45a1dcf67aa36604e7ac9..2ab2d273f08c2535c37c3696f4d440f6ba4038e1 100644
--- a/src/jsregexp.cc
+++ b/src/jsregexp.cc
@@ -236,23 +236,19 @@ MaybeHandle<Object> RegExpImpl::Compile(Handle<JSRegExp> re,
 }
 
 
-Handle<Object> RegExpImpl::Exec(Handle<JSRegExp> regexp,
-                                Handle<String> subject,
-                                int index,
-                                Handle<JSArray> last_match_info) {
+MaybeHandle<Object> RegExpImpl::Exec(Handle<JSRegExp> regexp,
+                                     Handle<String> subject,
+                                     int index,
+                                     Handle<JSArray> last_match_info) {
   switch (regexp->TypeTag()) {
     case JSRegExp::ATOM:
       return AtomExec(regexp, subject, index, last_match_info);
     case JSRegExp::IRREGEXP: {
-      Handle<Object> result =
-          IrregexpExec(regexp, subject, index, last_match_info);
-      ASSERT(!result.is_null() ||
-             regexp->GetIsolate()->has_pending_exception());
-      return result;
+      return IrregexpExec(regexp, subject, index, last_match_info);
     }
     default:
       UNREACHABLE();
-      return Handle<Object>::null();
+      return MaybeHandle<Object>();
   }
 }
 
@@ -641,10 +637,10 @@ int RegExpImpl::IrregexpExecRaw(Handle<JSRegExp> regexp,
 }
 
 
-Handle<Object> RegExpImpl::IrregexpExec(Handle<JSRegExp> regexp,
-                                        Handle<String> subject,
-                                        int previous_index,
-                                        Handle<JSArray> last_match_info) {
+MaybeHandle<Object> RegExpImpl::IrregexpExec(Handle<JSRegExp> regexp,
+                                             Handle<String> subject,
+                                             int previous_index,
+                                             Handle<JSArray> last_match_info) {
   Isolate* isolate = regexp->GetIsolate();
   ASSERT_EQ(regexp->TypeTag(), JSRegExp::IRREGEXP);
 
@@ -660,7 +656,7 @@ Handle<Object> RegExpImpl::IrregexpExec(Handle<JSRegExp> regexp,
   if (required_registers < 0) {
     // Compiling failed with an exception.
     ASSERT(isolate->has_pending_exception());
-    return Handle<Object>::null();
+    return MaybeHandle<Object>();
   }
 
   int32_t* output_registers = NULL;
@@ -682,7 +678,7 @@ Handle<Object> RegExpImpl::IrregexpExec(Handle<JSRegExp> regexp,
   }
   if (res == RE_EXCEPTION) {
     ASSERT(isolate->has_pending_exception());
-    return Handle<Object>::null();
+    return MaybeHandle<Object>();
   }
   ASSERT(res == RE_FAILURE);
   return isolate->factory()->null_value();