CR: simplify

Signal/src/ViewControllers/ConversationView/Cells/OWSBubbleView.m

@@ -161,16 +161,13 @@ const CGFloat kOWSMessageCellCornerRadius_Small = 2;
     CGFloat bottomRounding
         = (useSmallCorners_Bottom ? kOWSMessageCellCornerRadius_Small : kOWSMessageCellCornerRadius_Large);
 
-    const CGFloat topAngle = 3.0f * M_PI / 2.0f;
+    const CGFloat topAngle = 3.0f * M_PI_2;
     const CGFloat rightAngle = 0.0f;
-    const CGFloat bottomAngle = M_PI / 2.0f;
+    const CGFloat bottomAngle = M_PI_2;
     const CGFloat leftAngle = M_PI;
 
     [bezierPath moveToPoint:CGPointMake(bubbleLeft + topRounding, bubbleTop)];
 
-    // top line
-    [bezierPath addLineToPoint:CGPointMake(bubbleRight - topRounding, bubbleTop)];
-
     // top right corner
     [bezierPath addArcWithCenter:CGPointMake(bubbleRight - topRounding, bubbleTop + topRounding)
                           radius:topRounding
@@ -178,9 +175,6 @@ const CGFloat kOWSMessageCellCornerRadius_Small = 2;
                         endAngle:rightAngle
                        clockwise:true];
 
-    // right line
-    [bezierPath addLineToPoint:CGPointMake(bubbleRight, bubbleBottom - bottomRounding)];
-
     // bottom right corner
     [bezierPath addArcWithCenter:CGPointMake(bubbleRight - bottomRounding, bubbleBottom - bottomRounding)
                           radius:bottomRounding
@@ -188,9 +182,6 @@ const CGFloat kOWSMessageCellCornerRadius_Small = 2;
                         endAngle:bottomAngle
                        clockwise:true];
 
-    // bottom line
-    [bezierPath addLineToPoint:CGPointMake(bubbleLeft + bottomRounding, bubbleBottom)];
-
     // bottom left corner
     [bezierPath addArcWithCenter:CGPointMake(bubbleLeft + bottomRounding, bubbleBottom - bottomRounding)
                           radius:bottomRounding
@@ -198,9 +189,6 @@ const CGFloat kOWSMessageCellCornerRadius_Small = 2;
                         endAngle:leftAngle
                        clockwise:true];
 
-    // left line
-    [bezierPath addLineToPoint:CGPointMake(bubbleLeft, bubbleTop + topRounding)];
-
     // top left corner
     [bezierPath addArcWithCenter:CGPointMake(bubbleLeft + topRounding, bubbleTop + topRounding)
                           radius:topRounding