mac: Don't use kWebURLsWithTitlesPboardType from third_party/mozilla

chrome/browser/ui/cocoa/url_drop_target.mm

Index: chrome/browser/ui/cocoa/url_drop_target.mm
diff --git a/chrome/browser/ui/cocoa/url_drop_target.mm b/chrome/browser/ui/cocoa/url_drop_target.mm
index ef4758f6e221efbb3388ae2c9dc7f8a359ffb2be..71fa844f3eb6c04f9e76391ec12c0f0f5b66b5d5 100644
--- a/chrome/browser/ui/cocoa/url_drop_target.mm
+++ b/chrome/browser/ui/cocoa/url_drop_target.mm
@@ -9,6 +9,15 @@
 #include "googleurl/src/gurl.h"
 #import "third_party/mozilla/NSPasteboard+Utils.h"
 
+namespace {
+
+// Mac WebKit uses this type, declared in
+// WebKit/mac/History/WebURLsWithTitles.h.
+NSString* const kCrWebURLsWithTitlesPboardType =
+    @"WebURLsWithTitlesPboardType";
+
+}  // namespace
+
 @interface URLDropTargetHandler(Private)
 
 // Gets the appropriate drag operation given the |NSDraggingInfo|.
@@ -22,7 +31,7 @@
 @implementation URLDropTargetHandler
 
 + (NSArray*)handledDragTypes {
-  return [NSArray arrayWithObjects:kWebURLsWithTitlesPboardType,
+  return [NSArray arrayWithObjects:kCrWebURLsWithTitlesPboardType,
                                    NSURLPboardType,
                                    NSStringPboardType,
                                    NSFilenamesPboardType,