Make reprioritization IPC batch rather than per-request.

content/common/resource_messages.h

Index: content/common/resource_messages.h
diff --git a/content/common/resource_messages.h b/content/common/resource_messages.h
index 50c828fa05ee10101d86f44b5e9314106d5716d5..bfaece5bf4983897538b0ae9b9c318233f2329f0 100644
--- a/content/common/resource_messages.h
+++ b/content/common/resource_messages.h
@@ -14,6 +14,7 @@
 #include "base/process/process.h"
 #include "content/common/content_param_traits_macros.h"
 #include "content/common/navigation_params.h"
+#include "content/common/resource_priority_change_info.h"
 #include "content/common/resource_request.h"
 #include "content/common/resource_request_body_impl.h"
 #include "content/common/resource_request_completion_status.h"
@@ -21,7 +22,6 @@
 #include "content/public/common/common_param_traits.h"
 #include "content/public/common/resource_response.h"
 #include "ipc/ipc_message_macros.h"
-#include "net/base/request_priority.h"
 #include "net/cert/signed_certificate_timestamp.h"
 #include "net/cert/signed_certificate_timestamp_and_status.h"
 #include "net/http/http_response_info.h"
@@ -263,6 +263,13 @@ IPC_STRUCT_TRAITS_BEGIN(content::ResourceRequestCompletionStatus)
   IPC_STRUCT_TRAITS_MEMBER(encoded_body_length)
 IPC_STRUCT_TRAITS_END()
 
+// Parameters for ResourceHostMsg_DidChangePriority
+IPC_STRUCT_TRAITS_BEGIN(content::ResourcePriorityChangeInfo)
+  IPC_STRUCT_TRAITS_MEMBER(request_id)
+  IPC_STRUCT_TRAITS_MEMBER(priority)
+  IPC_STRUCT_TRAITS_MEMBER(intra_priority_value)
+IPC_STRUCT_TRAITS_END()
+
 // Resource messages sent from the browser to the renderer.
 
 // Sent when the headers are available for a resource request.
@@ -373,8 +380,6 @@ IPC_MESSAGE_CONTROL1(ResourceHostMsg_UploadProgress_ACK,
 IPC_MESSAGE_CONTROL1(ResourceHostMsg_ReleaseDownloadedFile,
                      int /* request_id */)
 
-// Sent by the renderer when a resource request changes priority.
-IPC_MESSAGE_CONTROL3(ResourceHostMsg_DidChangePriority,
-                     int /* request_id */,
-                     net::RequestPriority,
-                     int /* intra_priority_value */)
+// Sent by the renderer when resource requests changes priority.
+IPC_MESSAGE_CONTROL1(ResourceHostMsg_DidChangePriority,
+                     std::vector<content::ResourcePriorityChangeInfo>);