PROTOTYPE: PlzNavigate: use a Mojo data pipe to stream navigation data to the renderer.

content/child/resource_dispatcher.h

Index: content/child/resource_dispatcher.h
diff --git a/content/child/resource_dispatcher.h b/content/child/resource_dispatcher.h
index 9b07c8265a7b7c369fe5a27f65dca4723a196b05..df42bd76ec43d734ce6f21341bb92b9531dd2fa6 100644
--- a/content/child/resource_dispatcher.h
+++ b/content/child/resource_dispatcher.h
@@ -25,6 +25,8 @@
 #include "content/public/common/resource_type.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
+#include "mojo/public/cpp/system/data_pipe.h"
+#include "mojo/public/cpp/system/watcher.h"
 #include "net/base/request_priority.h"
 #include "url/gurl.h"
 
@@ -74,9 +76,12 @@ class CONTENT_EXPORT ResourceDispatcher : public IPC::Listener {
   // Call this method to initiate the request. If this method succeeds, then
   // the peer's methods will be called asynchronously to report various events.
   // Returns the request id.
-  virtual int StartAsync(const RequestInfo& request_info,
-                         ResourceRequestBody* request_body,
-                         scoped_ptr<RequestPeer> peer);
+  virtual int StartAsync(
+      const RequestInfo& request_info,
+      ResourceRequestBody* request_body,
+      scoped_ptr<RequestPeer> peer,
+      mojo::ScopedDataPipeConsumerHandle mojo_data_pipe_handle,
+      int browser_request_id);
 
   // Removes a request from the |pending_requests_| list, returning true if the
   // request was found and removed.
@@ -157,6 +162,10 @@ class CONTENT_EXPORT ResourceDispatcher : public IPC::Listener {
     scoped_refptr<SharedMemoryReceivedDataFactory> received_data_factory;
     scoped_ptr<SiteIsolationResponseMetaData> site_isolation_metadata;
     int buffer_size;
+
+    mojo::ScopedDataPipeConsumerHandle mojo_data_pipe_handle;
+    mojo::Watcher mojo_watcher;
+    uint32_t mojo_total_bytes;
   };
   using PendingRequestMap = std::map<int, scoped_ptr<PendingRequestInfo>>;
 
@@ -197,6 +206,13 @@ class CONTENT_EXPORT ResourceDispatcher : public IPC::Listener {
   // again in the deferred state. This method may mutate |pending_requests_|.
   void FlushDeferredMessages(int request_id);
 
+  // PlzNavigate: Mojo data streaming methods
+  void WaitForMojoData(int request_id, PendingRequestInfo* request_info);
+  void ReceivedMojoData(int request_id, MojoResult);
+  void AcceptMojoMessage(PendingRequestInfo* request_info,
+                         const void* buffer,
+                         uint32_t num_bytes);
+
   void ToResourceResponseInfo(const PendingRequestInfo& request_info,
                               const ResourceResponseHead& browser_info,
                               ResourceResponseInfo* renderer_info) const;