Fix component build after HyperlinkTextView move.

HyperlinkTextView moved components in 0e6cd43e; this marks it as being exported for use in other components.

BUG=402485
TEST=component build builds

Review URL: https://codereview.chromium.org/602093004

Cr-Commit-Position: refs/heads/master@{#296787}

ui/base/cocoa/controls/hyperlink_text_view.h

@@ -4,11 +4,14 @@
 
 #import <Cocoa/Cocoa.h>
 
+#include "ui/base/ui_base_export.h"
+
 @class NSColor;
 
 // HyperlinkTextView is an NSTextView subclass for unselectable, linkable text.
 // This subclass doesn't show the text caret or IBeamCursor, whereas the base
 // class NSTextView displays both with full keyboard accessibility enabled.
+UI_BASE_EXPORT
 @interface HyperlinkTextView : NSTextView {
  @private
   BOOL refusesFirstResponder_;