Introduces a new MHTML generation parameter specifying different behvaior for cache-control headers.

content/common/frame_messages.h

Index: content/common/frame_messages.h
diff --git a/content/common/frame_messages.h b/content/common/frame_messages.h
index e514f2d3f560c1809f14992889077174644639d6..b94a2c711ed9945ec198b32330c04aa9389c8fe1 100644
--- a/content/common/frame_messages.h
+++ b/content/common/frame_messages.h
@@ -31,6 +31,7 @@
 #include "content/public/common/frame_navigate_params.h"
 #include "content/public/common/javascript_message_type.h"
 #include "content/public/common/message_port_types.h"
+#include "content/public/common/mhtml_generation.h"
 #include "content/public/common/page_importance_signals.h"
 #include "content/public/common/page_state.h"
 #include "content/public/common/resource_response.h"
@@ -501,6 +502,9 @@ IPC_STRUCT_BEGIN(FrameMsg_SerializeAsMHTML_Params)
   // intended for sharing.
   IPC_STRUCT_MEMBER(bool, mhtml_binary_encoding)
 
+  IPC_STRUCT_MEMBER(content::MHTMLCacheControlPolicy,
+                    mhtml_cache_control_policy)
+
   // Frame to content-id map.
   // Keys are routing ids of either RenderFrames or RenderFrameProxies.
   // Values are MHTML content-ids - see WebFrameSerializer::generateMHTMLParts.
@@ -1385,7 +1389,7 @@ IPC_MESSAGE_ROUTED2(FrameHostMsg_SerializedHtmlWithLocalLinksResponse,
 IPC_MESSAGE_ROUTED3(
     FrameHostMsg_SerializeAsMHTMLResponse,
     int /* job_id (used to match responses to requests) */,
-    bool /* true if success, false if error */,
+    content::MHTMLSerializationResult /* result of serialization */,
     std::set<std::string> /* digests of uris of serialized resources */)
 
 // Sent when the renderer updates hint for importance of a tab.