Blobs: Catching browser-process created Blobs in extension code.

extensions/common/extension_messages.h

Index: extensions/common/extension_messages.h
diff --git a/extensions/common/extension_messages.h b/extensions/common/extension_messages.h
index 9bb15abaa89535afc5ec304b2f0804e2ff4b6fd9..e8eb1b6fa0af72c05f288ad70cc656f6471b9151 100644
--- a/extensions/common/extension_messages.h
+++ b/extensions/common/extension_messages.h
@@ -455,6 +455,14 @@ IPC_MESSAGE_ROUTED0(ExtensionMsg_AppWindowClosed)
 IPC_MESSAGE_CONTROL1(ExtensionMsg_WatchPages,
                      std::vector<std::string> /* CSS selectors */)
 
+// Send by the browser to indicate a Blob handle has been transferred to the
+// renderer. This is sent after the actual extension response, and depends on
+// the sequential nature of IPCs so that the blob has already been caught.
+// This is a separate control message, so that the renderer process will send
+// an acknowledgement even if the RenderView has closed or navigated away.
+IPC_MESSAGE_CONTROL1(ExtensionMsg_TransferBlobs,
+                     std::vector<std::string> /* blob_uuids */)
+
 // Messages sent from the renderer to the browser.
 
 // A renderer sends this message when an extension process starts an API
@@ -642,3 +650,7 @@ IPC_MESSAGE_CONTROL2(ExtensionHostMsg_AddDOMActionToActivityLog,
 //   to change.
 IPC_MESSAGE_ROUTED1(ExtensionHostMsg_OnWatchedPageChange,
                     std::vector<std::string> /* Matching CSS selectors */)
+
+// Sent by the renderer when it has received a Blob handle from the browser.
+IPC_MESSAGE_CONTROL1(ExtensionHostMsg_TransferBlobsAck,
+                     std::vector<std::string> /* blob_uuids */)