Add line height setting to views::Label & use it for notifications.

ui/message_center/message_center_constants.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_MESSAGE_CENTER_MESSAGE_CENTER_CONSTANTS_H_
 #define UI_MESSAGE_CENTER_MESSAGE_CENTER_CONSTANTS_H_
 
 #include "base/basictypes.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/message_center/message_center_export.h"
@@ skipping 10 matching lines @@
 
 // Within a notification ///////////////////////////////////////////////////////
 
 // Pixel dimensions (H = horizontal, V = vertical).
 extern const int kControlButtonSize;  // Square size of close & expand buttons.
 extern const int kNotificationWidth;  // H size of the whole card.
 extern const int kIconToTextPadding;  // H space between icon & title/message.
 extern const int kTextTopPadding;     // V space between text elements.
 
 // Text sizes.
-extern const int kTitleFontSize;    // For title only.
-extern const int kMessageFontSize;  // For everything but title.
+extern const int kTitleFontSize;      // For title only.
+extern const int kMessageFontSize;    // For everything but title.
+extern const int kMessageLineHeight;  // In pixels.
 
 // Colors.
 extern const SkColor kNotificationBackgroundColor; // Background of the card.
 extern const SkColor kLegacyIconBackgroundColor;   // Used behind icons smaller.
                                                    // than the icon view.
 extern const SkColor kRegularTextColor;            // Title, message, ...
 extern const SkColor kFocusBorderColor;            // The focus border.
 
 // Limits.
 extern const int kNotificationMaximumImageHeight;  // For image notifications.
 extern const size_t kNotificationMaximumItems;     // For list notifications.
 
 // Timing.
 extern const int kAutocloseDefaultDelaySeconds;
 extern const int kAutocloseHighPriorityDelaySeconds;
 
 // Around notifications ////////////////////////////////////////////////////////
 
 // Pixel dimensions (H = horizontal, V = vertical).
 extern const int kMarginBetweenItems; // H & V space around & between
                                       // notifications.
 
 // Colors.
 extern const SkColor kBackgroundLightColor;  // Behind notifications, gradient
 extern const SkColor kBackgroundDarkColor;   // from light to dark.
 
 }  // namespace message_center
 
 #endif  // UI_MESSAGE_CENTER_MESSAGE_CENTER_CONSTANTS_H_