Empty string check optimization (#3826)

Author: Youssef1313

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/FormatControl.cs

@@ -261,7 +261,7 @@ private void UpdateControlVisibility(FormatTypeClass formatType)
             }
 
             tableLayoutPanel1.SuspendLayout();
-            secondRowLabel.Text = "";
+            secondRowLabel.Text = string.Empty;
 
             // process the decimalPlacesLabelVisible
             if (formatType.DropDownVisible)
@@ -315,14 +315,7 @@ private void UpdateControlVisibility(FormatTypeClass formatType)
                 dateTimeFormatsListBox.Visible = false;
             }
 
-            if (secondRowLabel.Text == "")
-            {
-                secondRowLabel.Visible = false;
-            }
-            else
-            {
-                secondRowLabel.Visible = true;
-            }
+            secondRowLabel.Visible = secondRowLabel.Text.Length > 0;
 
             tableLayoutPanel1.ResumeLayout(true /*performLayout*/);
         }

src/System.Windows.Forms/src/System/Windows/Forms/WebBrowser.cs

@@ -611,7 +611,7 @@ public Uri Url
             }
             set
             {
-                if (value != null && value.ToString() == "")
+                if (value != null && value.ToString().Length == 0)
                 {
                     value = null;
                 }