Fix NSPasteboard leaks.

ui/base/clipboard/clipboard_util_mac.mm

Index: ui/base/clipboard/clipboard_util_mac.mm
diff --git a/ui/base/clipboard/clipboard_util_mac.mm b/ui/base/clipboard/clipboard_util_mac.mm
index 0d3f8f87fa64bfca4badd049625f02ed6d3962d3..433e668e8dbed3a6c22de2e8424a35aa42063e5a 100644
--- a/ui/base/clipboard/clipboard_util_mac.mm
+++ b/ui/base/clipboard/clipboard_util_mac.mm
@@ -26,6 +26,13 @@ NSString* UTIFromPboardType(NSString* type) {
 
 namespace ui {
 
+UniquePasteboard::UniquePasteboard()
+    : pasteboard_([[NSPasteboard pasteboardWithUniqueName] retain]) {}
+
+UniquePasteboard::~UniquePasteboard() {
+  [pasteboard_ releaseGlobally];

[Avi (use Gerrit), 2016/04/01 18:21:01]

OMG

Yes, the docs imply this, but this isn't at all obvious.

o_O

+}
+
 // static
 base::scoped_nsobject<NSPasteboardItem> ClipboardUtil::PasteboardItemFromUrl(
     NSString* urlString,