Remove unnecessary styling for some controls in ARDMainView.m for ios.

They can be removed and we can use the default system controls.
It's less code and also has more native look.

BUG=webrtc:6617

Review-Url: https://codereview.webrtc.org/2455413002
Cr-Commit-Position: refs/heads/master@{#14882}

webrtc/examples/objc/AppRTCMobile/ios/ARDMainView.m

@@ -12,10 +12,6 @@
 
 #import "UIImage+ARDUtilities.h"
 
-// TODO(tkchin): retrieve status bar height dynamically.
-static CGFloat const kStatusBarHeight = 20;
-
-static CGFloat const kRoomTextButtonSize = 40;
 static CGFloat const kRoomTextFieldHeight = 40;
 static CGFloat const kRoomTextFieldMargin = 8;
 static CGFloat const kCallControlMargin = 8;
@@ -27,7 +23,6 @@ static CGFloat const kCallControlMargin = 8;
 
 @implementation ARDRoomTextField {
   UITextField *_roomText;
-  UIButton *_clearButton;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame {
@@ -38,23 +33,10 @@ static CGFloat const kCallControlMargin = 8;
     _roomText.placeholder = @"Room name";
     _roomText.autocorrectionType = UITextAutocorrectionTypeNo;
     _roomText.autocapitalizationType = UITextAutocapitalizationTypeNone;
+    _roomText.clearButtonMode = UITextFieldViewModeAlways;
     _roomText.delegate = self;
-    [_roomText addTarget:self
-                  action:@selector(textFieldDidChange:)
-        forControlEvents:UIControlEventEditingChanged];
     [self addSubview:_roomText];
 
-    _clearButton = [UIButton buttonWithType:UIButtonTypeCustom];
-    UIImage *image = [UIImage imageForName:@"ic_clear_black_24dp.png"
-                                     color:[UIColor colorWithWhite:0 alpha:.4]];
-
-    [_clearButton setImage:image forState:UIControlStateNormal];
-    [_clearButton addTarget:self
-                      action:@selector(onClear:)
-            forControlEvents:UIControlEventTouchUpInside];
-    _clearButton.hidden = YES;
-    [self addSubview:_clearButton];
-
     // Give rounded corners and a light gray border.
     self.layer.borderWidth = 1;
     self.layer.borderColor = [[UIColor lightGrayColor] CGColor];
@@ -64,17 +46,9 @@ static CGFloat const kCallControlMargin = 8;
 }
 
 - (void)layoutSubviews {
-  CGRect bounds = self.bounds;
-  _clearButton.frame = CGRectMake(CGRectGetMaxX(bounds) - kRoomTextButtonSize,
-                                  CGRectGetMinY(bounds),
-                                  kRoomTextButtonSize,
-                                  kRoomTextButtonSize);
-  _roomText.frame = CGRectMake(
-      CGRectGetMinX(bounds) + kRoomTextFieldMargin,
-      CGRectGetMinY(bounds),
-      CGRectGetMinX(_clearButton.frame) - CGRectGetMinX(bounds) -
-          kRoomTextFieldMargin,
-      kRoomTextFieldHeight);
+  _roomText.frame =
+      CGRectMake(kRoomTextFieldMargin, 0, CGRectGetWidth(self.bounds) - kRoomTextFieldMargin,
+                 kRoomTextFieldHeight);
 }
 
 - (CGSize)sizeThatFits:(CGSize)size {
@@ -95,22 +69,6 @@ static CGFloat const kCallControlMargin = 8;
   return YES;
 }
 
-#pragma mark - Private
-
-- (void)textFieldDidChange:(id)sender {
-  [self updateClearButton];
-}
-
-- (void)onClear:(id)sender {
-  _roomText.text = @"";
-  [self updateClearButton];
-  [_roomText resignFirstResponder];
-}
-
-- (void)updateClearButton {
-  _clearButton.hidden = _roomText.text.length == 0;
-}
-
 @end
 
 @implementation ARDMainView {
@@ -205,17 +163,9 @@ static CGFloat const kCallControlMargin = 8;
     [self addSubview:_useManualAudioLabel];
 
     _startCallButton = [UIButton buttonWithType:UIButtonTypeSystem];
-    _startCallButton.backgroundColor = [UIColor blueColor];
-    _startCallButton.layer.cornerRadius = 10;
-    _startCallButton.clipsToBounds = YES;
-    _startCallButton.contentEdgeInsets = UIEdgeInsetsMake(5, 10, 5, 10);
     [_startCallButton setTitle:@"Start call"
                       forState:UIControlStateNormal];
     _startCallButton.titleLabel.font = controlFont;
-    [_startCallButton setTitleColor:[UIColor whiteColor]
-                           forState:UIControlStateNormal];
-    [_startCallButton setTitleColor:[UIColor lightGrayColor]
-                           forState:UIControlStateSelected];
     [_startCallButton sizeToFit];
     [_startCallButton addTarget:self
                          action:@selector(onStartCall:)
@@ -224,14 +174,7 @@ static CGFloat const kCallControlMargin = 8;
 
     // Used to test what happens to sounds when calls are in progress.
     _audioLoopButton = [UIButton buttonWithType:UIButtonTypeSystem];
-    _audioLoopButton.layer.cornerRadius = 10;
-    _audioLoopButton.clipsToBounds = YES;
-    _audioLoopButton.contentEdgeInsets = UIEdgeInsetsMake(5, 10, 5, 10);
     _audioLoopButton.titleLabel.font = controlFont;
-    [_audioLoopButton setTitleColor:[UIColor whiteColor]
-                           forState:UIControlStateNormal];
-    [_audioLoopButton setTitleColor:[UIColor lightGrayColor]
-                           forState:UIControlStateSelected];
     [self updateAudioLoopButton];
     [_audioLoopButton addTarget:self
                          action:@selector(onToggleAudioLoop:)
@@ -346,12 +289,10 @@ static CGFloat const kCallControlMargin = 8;
 
 - (void)updateAudioLoopButton {
   if (_isAudioLoopPlaying) {
-    _audioLoopButton.backgroundColor = [UIColor redColor];
     [_audioLoopButton setTitle:@"Stop sound"
                       forState:UIControlStateNormal];
     [_audioLoopButton sizeToFit];
   } else {
-    _audioLoopButton.backgroundColor = [UIColor greenColor];
     [_audioLoopButton setTitle:@"Play sound"
                       forState:UIControlStateNormal];
     [_audioLoopButton sizeToFit];