Set minimal width for the username in the password bubble on Mac.

chrome/browser/ui/cocoa/passwords/passwords_bubble_utils.mm

Index: chrome/browser/ui/cocoa/passwords/passwords_bubble_utils.mm
diff --git a/chrome/browser/ui/cocoa/passwords/passwords_bubble_utils.mm b/chrome/browser/ui/cocoa/passwords/passwords_bubble_utils.mm
index 332d4c7f24a6acd42788e7585293d96c4fad0647..7ccd22a3e9098091bccb217cf90684511766bb53 100644
--- a/chrome/browser/ui/cocoa/passwords/passwords_bubble_utils.mm
+++ b/chrome/browser/ui/cocoa/passwords/passwords_bubble_utils.mm
@@ -73,6 +73,7 @@ void InitLabel(NSTextField* textField, const base::string16& text) {
 std::pair<CGFloat, CGFloat> GetResizedColumns(
     CGFloat maxWidth,
     std::pair<CGFloat, CGFloat> columnsWidth) {
+  DCHECK_GE(maxWidth, kItemLabelSpacing + kMinUsernameSize);
   // Free space can be negative.
   CGFloat freeSpace =
       maxWidth - (columnsWidth.first + columnsWidth.second + kItemLabelSpacing);
@@ -83,9 +84,11 @@ std::pair<CGFloat, CGFloat> GetResizedColumns(
   // Make sure that the sizes are nonnegative.
   CGFloat firstColumnPercent =
       columnsWidth.first / (columnsWidth.first + columnsWidth.second);
+  CGFloat firstColumnSize = std::max(
+      kMinUsernameSize, columnsWidth.first + freeSpace * firstColumnPercent);
   return std::make_pair(
-      columnsWidth.first + freeSpace * firstColumnPercent,
-      columnsWidth.second + freeSpace * (1 - firstColumnPercent));
+      firstColumnSize,
+      maxWidth - kItemLabelSpacing - firstColumnSize);
 }
 
 NSSecureTextField* PasswordLabel(const base::string16& text) {