Use mojo for Chrome Loading, Part 1

content/browser/loader/resource_dispatcher_host_impl.cc

Index: content/browser/loader/resource_dispatcher_host_impl.cc
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index da256df980413b76fe334efae34d9216b3394399..fbf4f7dcbd08a5eb1ab56888d02e5de28d7c3549 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -50,6 +50,7 @@
 #include "content/browser/loader/cross_site_resource_handler.h"
 #include "content/browser/loader/detachable_resource_handler.h"
 #include "content/browser/loader/mime_type_resource_handler.h"
+#include "content/browser/loader/mojo_async_resource_handler.h"
 #include "content/browser/loader/navigation_resource_handler.h"
 #include "content/browser/loader/navigation_resource_throttle.h"
 #include "content/browser/loader/navigation_url_loader_impl_core.h"
@@ -229,7 +230,8 @@ bool IsDetachableResourceType(ResourceType type) {
 // Aborts a request before an URLRequest has actually been created.
 void AbortRequestBeforeItStarts(ResourceMessageFilter* filter,
                                 IPC::Message* sync_result,
-                                int request_id) {
+                                int request_id,
+                                mojom::URLLoaderClientPtr url_loader_client) {
   if (sync_result) {
     SyncLoadResult result;
     result.error_code = net::ERR_ABORTED;
@@ -244,8 +246,12 @@ void AbortRequestBeforeItStarts(ResourceMessageFilter* filter,
     // No security info needed, connection not established.
     request_complete_data.completion_time = base::TimeTicks();
     request_complete_data.encoded_data_length = 0;
-    filter->Send(new ResourceMsg_RequestComplete(
-        request_id, request_complete_data));
+    if (url_loader_client) {
+      url_loader_client->OnComplete(request_complete_data);
+    } else {
+      filter->Send(
+          new ResourceMsg_RequestComplete(request_id, request_complete_data));
+    }
   }
 }
 
@@ -584,6 +590,7 @@ ResourceDispatcherHostImpl::ResourceDispatcherHostImpl()
 ResourceDispatcherHostImpl::~ResourceDispatcherHostImpl() {
   DCHECK(outstanding_requests_stats_map_.empty());
   DCHECK(g_resource_dispatcher_host);
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
   g_resource_dispatcher_host = NULL;
 }
 
@@ -1178,6 +1185,7 @@ void ResourceDispatcherHostImpl::OnShutdown() {
 bool ResourceDispatcherHostImpl::OnMessageReceived(
     const IPC::Message& message,
     ResourceMessageFilter* filter) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
   filter_ = filter;
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ResourceDispatcherHostImpl, message)
@@ -1219,6 +1227,16 @@ void ResourceDispatcherHostImpl::OnRequestResource(
     int routing_id,
     int request_id,
     const ResourceRequest& request_data) {
+  OnRequestResourceInternal(routing_id, request_id, request_data, nullptr,
+                            nullptr);
+}
+
+void ResourceDispatcherHostImpl::OnRequestResourceInternal(
+    int routing_id,
+    int request_id,
+    const ResourceRequest& request_data,
+    std::unique_ptr<mojom::URLLoader> url_loader,
+    mojom::URLLoaderClientPtr url_loader_client) {
   // TODO(pkasting): Remove ScopedTracker below once crbug.com/477117 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
@@ -1239,7 +1257,8 @@ void ResourceDispatcherHostImpl::OnRequestResource(
                    request_data.render_frame_id,
                    request_data.url));
   }
-  BeginRequest(request_id, request_data, NULL, routing_id);
+  BeginRequest(request_id, request_data, NULL, routing_id,
+               std::move(url_loader), std::move(url_loader_client));
 }
 
 // Begins a resource request with the given params on behalf of the specified
@@ -1253,8 +1272,8 @@ void ResourceDispatcherHostImpl::OnRequestResource(
 void ResourceDispatcherHostImpl::OnSyncLoad(int request_id,
                                             const ResourceRequest& request_data,
                                             IPC::Message* sync_result) {
-  BeginRequest(request_id, request_data, sync_result,
-               sync_result->routing_id());
+  BeginRequest(request_id, request_data, sync_result, sync_result->routing_id(),
+               nullptr, nullptr);
 }
 
 bool ResourceDispatcherHostImpl::IsRequestIDInUse(
@@ -1369,7 +1388,9 @@ void ResourceDispatcherHostImpl::BeginRequest(
     int request_id,
     const ResourceRequest& request_data,
     IPC::Message* sync_result,  // only valid for sync
-    int route_id) {
+    int route_id,
+    std::unique_ptr<mojom::URLLoader> url_loader,
+    mojom::URLLoaderClientPtr url_loader_client) {
   int process_type = filter_->process_type();
   int child_id = filter_->child_id();
 
@@ -1438,7 +1459,8 @@ void ResourceDispatcherHostImpl::BeginRequest(
   if (is_shutdown_ ||
       !ShouldServiceRequest(process_type, child_id, request_data, headers,
                             filter_, resource_context)) {
-    AbortRequestBeforeItStarts(filter_, sync_result, request_id);
+    AbortRequestBeforeItStarts(filter_, sync_result, request_id,
+                               std::move(url_loader_client));
     return;
   }
 
@@ -1447,7 +1469,8 @@ void ResourceDispatcherHostImpl::BeginRequest(
                                                   request_data.url,
                                                   request_data.resource_type,
                                                   resource_context)) {
-    AbortRequestBeforeItStarts(filter_, sync_result, request_id);
+    AbortRequestBeforeItStarts(filter_, sync_result, request_id,
+                               std::move(url_loader_client));
     return;
   }
 
@@ -1628,7 +1651,8 @@ void ResourceDispatcherHostImpl::BeginRequest(
 
   std::unique_ptr<ResourceHandler> handler(CreateResourceHandler(
       new_request.get(), request_data, sync_result, route_id, process_type,
-      child_id, resource_context));
+      child_id, resource_context, std::move(url_loader),
+      std::move(url_loader_client)));
 
   if (handler)
     BeginRequestInternal(std::move(new_request), std::move(handler));
@@ -1642,7 +1666,9 @@ ResourceDispatcherHostImpl::CreateResourceHandler(
     int route_id,
     int process_type,
     int child_id,
-    ResourceContext* resource_context) {
+    ResourceContext* resource_context,
+    std::unique_ptr<mojom::URLLoader> url_loader,
+    mojom::URLLoaderClientPtr url_loader_client) {
   // TODO(pkasting): Remove ScopedTracker below once crbug.com/456331 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
@@ -1656,9 +1682,16 @@ ResourceDispatcherHostImpl::CreateResourceHandler(
       return std::unique_ptr<ResourceHandler>();
     }
 
+    DCHECK(!url_loader);
+    DCHECK(!url_loader_client);
     handler.reset(new SyncResourceHandler(request, sync_result, this));
   } else {
-    handler.reset(new AsyncResourceHandler(request, this));
+    if (url_loader) {
+      handler.reset(new MojoAsyncResourceHandler(
+          request, this, std::move(url_loader), std::move(url_loader_client)));
+    } else {
+      handler.reset(new AsyncResourceHandler(request, this));
+    }
 
     // The RedirectToFileResourceHandler depends on being next in the chain.
     if (request_data.download_to_file) {
@@ -2064,6 +2097,19 @@ void ResourceDispatcherHostImpl::CancelRequestsForRoute(
       CancelBlockedRequestsForRoute(route_id);
     }
   }
+
+  // Unstarted URLLoader has no routing ID, so it should be deleted only when
+  // cancel_all_routes is specified.
+  if (cancel_all_routes) {
+    auto it = unstarted_url_loaders_.begin();
+    while (it != unstarted_url_loaders_.end()) {
+      if (it->second.first == child_id) {
+        it = unstarted_url_loaders_.erase(it);
+      } else {
+        ++it;
+      }
+    }
+  }
 }
 
 // Cancels the request and removes it from the list.
@@ -2351,6 +2397,38 @@ void ResourceDispatcherHostImpl::EnableStaleWhileRevalidateForTesting() {
     async_revalidation_manager_.reset(new AsyncRevalidationManager);
 }
 
+void ResourceDispatcherHostImpl::OnRequestResourceWithMojo(
+    int routing_id,
+    int request_id,
+    const ResourceRequest& request,
+    std::unique_ptr<mojom::URLLoader> url_loader,
+    mojom::URLLoaderClientPtr url_loader_client,
+    ResourceMessageFilter* filter) {
+  filter_ = filter;
+  OnRequestResourceInternal(routing_id, request_id, request,
+                            std::move(url_loader),
+                            std::move(url_loader_client));
+  filter_ = nullptr;
+}
+
+void ResourceDispatcherHostImpl::AddUnstartedURLLoader(
+    int child_id,
+    std::unique_ptr<mojom::URLLoader> loader) {
+  mojom::URLLoader* raw = loader.get();
+  unstarted_url_loaders_.insert(
+      std::make_pair(raw, std::make_pair(child_id, std::move(loader))));
+}
+
+std::unique_ptr<mojom::URLLoader>
+ResourceDispatcherHostImpl::TakeUnstartedURLLoader(mojom::URLLoader* loader) {
+  auto it = unstarted_url_loaders_.find(loader);
+  if (it == unstarted_url_loaders_.end())
+    return nullptr;
+  std::unique_ptr<mojom::URLLoader> result = std::move(it->second.second);
+  unstarted_url_loaders_.erase(it);
+  return result;
+}
+
 // static
 int ResourceDispatcherHostImpl::CalculateApproximateMemoryCost(
     net::URLRequest* request) {