MacViews: Partially implement OSExchangeDataProviderMac.

ui/base/dragdrop/os_exchange_data_provider_mac.h

Index: ui/base/dragdrop/os_exchange_data_provider_mac.h
diff --git a/ui/base/dragdrop/os_exchange_data_provider_mac.h b/ui/base/dragdrop/os_exchange_data_provider_mac.h
index 513239f6656145e4184394f0417063f43ec339b7..1e46e2e4ae0d9d0cb4e8561de1c163a8df603caa 100644
--- a/ui/base/dragdrop/os_exchange_data_provider_mac.h
+++ b/ui/base/dragdrop/os_exchange_data_provider_mac.h
@@ -5,8 +5,11 @@
 #ifndef UI_BASE_DRAGDROP_OS_EXCHANGE_DATA_PROVIDER_MAC_H_
 #define UI_BASE_DRAGDROP_OS_EXCHANGE_DATA_PROVIDER_MAC_H_
 
+#import "base/mac/scoped_nsobject.h"
 #include "ui/base/dragdrop/os_exchange_data.h"
 
+@class NSPasteboard;
+
 namespace ui {
 
 // OSExchangeData::Provider implementation for Mac.
@@ -14,6 +17,7 @@ class UI_BASE_EXPORT OSExchangeDataProviderMac
     : public OSExchangeData::Provider {
  public:
   OSExchangeDataProviderMac();
+  explicit OSExchangeDataProviderMac(NSPasteboard* pasteboard);
   virtual ~OSExchangeDataProviderMac();
 
   // Overridden from OSExchangeData::Provider:
@@ -42,6 +46,8 @@ class UI_BASE_EXPORT OSExchangeDataProviderMac
       const OSExchangeData::CustomFormat& format) const OVERRIDE;
 
  private:
+  base::scoped_nsobject<NSPasteboard> pasteboard_;
+
   DISALLOW_COPY_AND_ASSIGN(OSExchangeDataProviderMac);
 };