Review edits

Author: jmagman

shell/platform/darwin/ios/framework/Source/FlutterChannelKeyResponder.mm

@@ -135,7 +135,7 @@ - (void)handlePress:(nonnull FlutterUIPressProxy*)press
   NSString* characters = getEventCharacters(press.key.characters, press.key.keyCode);
   NSString* charactersIgnoringModifiers =
       getEventCharacters(press.key.charactersIgnoringModifiers, press.key.keyCode);
-  NSMutableDictionary* keyMessage = [@{
+  NSDictionary* keyMessage = @{
     @"keymap" : @"ios",
     @"type" : type,
     @"keyCode" : @(press.key.keyCode),
@@ -144,7 +144,7 @@ - (void)handlePress:(nonnull FlutterUIPressProxy*)press
     @"charactersIgnoringModifiers" : charactersIgnoringModifiers == nil
         ? @""
         : charactersIgnoringModifiers,
-  } mutableCopy];
+  };
   [self.channel sendMessage:keyMessage
                       reply:^(id reply) {
                         bool handled = reply ? [[reply valueForKey:@"handled"] boolValue] : true;

shell/platform/darwin/ios/framework/Source/FlutterSpellCheckPlugin.mm

@@ -102,7 +102,8 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
     }
   } while (nextSpellSuggestion != nil && nextOffset < text.length);
 
-  NSMutableArray* methodChannelResult = [[NSMutableArray alloc] init];
+  NSMutableArray* methodChannelResult =
+      [[NSMutableArray alloc] initWithCapacity:allSpellSuggestions.count];
 
   for (FlutterSpellCheckResult* result in allSpellSuggestions) {
     [methodChannelResult addObject:[result toDictionary]];