Move flash clipboard to the new proxy and add custom format support

ui/base/clipboard/clipboard_mac.mm

Index: ui/base/clipboard/clipboard_mac.mm
diff --git a/ui/base/clipboard/clipboard_mac.mm b/ui/base/clipboard/clipboard_mac.mm
index 03674480fca27de75271712b3dd754edc952c4c7..da915e3c58017f8303b022349846f89d8e8d4b0e 100644
--- a/ui/base/clipboard/clipboard_mac.mm
+++ b/ui/base/clipboard/clipboard_mac.mm
@@ -33,6 +33,10 @@ NSString* const kUTTypeURLName = @"public.url-name";
 // actual data associated with this type.
 NSString* const kWebSmartPastePboardType = @"NeXT smart paste pasteboard type";
 
+// Pepper custom data format type.
+NSString* const kPepperCustomDataPboardType =
+    @"org.chromium.pepper-custom-data";
+
 NSPasteboard* GetPasteboard() {
   // The pasteboard should not be nil in a UI session, but this handy DCHECK
   // can help track down problems if someone tries using clipboard code outside
@@ -475,4 +479,10 @@ const Clipboard::FormatType& Clipboard::GetWebCustomDataFormatType() {
   return type;
 }
 
+// static
+const Clipboard::FormatType& Clipboard::GetPepperCustomDataFormatType() {
+  CR_DEFINE_STATIC_LOCAL(FormatType, type, (kPepperCustomDataPboardType));
+  return type;
+}
+
 }  // namespace ui