Implement SetDefersLoading on content::URLLoaderClientImpl

content/child/url_response_body_consumer.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/url_response_body_consumer.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
@@ skipping 58 matching lines @@
   has_received_completion_ = true;
   completion_status_ = status;
   NotifyCompletionIfAppropriate();
 }
 
 void URLResponseBodyConsumer::Cancel() {
   has_been_cancelled_ = true;
   handle_watcher_.Cancel();
 }
 
+void URLResponseBodyConsumer::SetDefersLoading() {
+  is_deferred_ = true;
+}
+
+void URLResponseBodyConsumer::UnsetDefersLoading() {
+  is_deferred_ = false;
+  OnReadable(MOJO_RESULT_OK);
+}
+
 void URLResponseBodyConsumer::Reclaim(uint32_t size) {
   MojoResult result = mojo::EndReadDataRaw(handle_.get(), size);
   DCHECK_EQ(MOJO_RESULT_OK, result);
 
   if (is_in_on_readable_)
     return;
 
   task_runner_->PostTask(
       FROM_HERE, base::Bind(&URLResponseBodyConsumer::OnReadable, AsWeakPtr(),
                             MOJO_RESULT_OK));
 }
 
 void URLResponseBodyConsumer::OnReadable(MojoResult unused) {
+  if (has_been_cancelled_ || has_seen_end_of_data_ || is_deferred_)
+    return;
+
   DCHECK(!is_in_on_readable_);
 
-  if (has_been_cancelled_ || has_seen_end_of_data_)
-    return;
-
   // Protect |this| as RequestPeer::OnReceivedData may call deref.
   scoped_refptr<URLResponseBodyConsumer> protect(this);
   base::AutoReset<bool> is_in_on_readable(&is_in_on_readable_, true);
 
-  // TODO(yhirano): Suppress notification when deferred.
-  while (!has_been_cancelled_) {
+  while (!has_been_cancelled_ && !is_deferred_) {
     const void* buffer = nullptr;
     uint32_t available = 0;
     MojoResult result = mojo::BeginReadDataRaw(
         handle_.get(), &buffer, &available, MOJO_READ_DATA_FLAG_NONE);
     if (result == MOJO_RESULT_SHOULD_WAIT || result == MOJO_RESULT_BUSY)
       return;
     if (result == MOJO_RESULT_FAILED_PRECONDITION) {
       has_seen_end_of_data_ = true;
       NotifyCompletionIfAppropriate();
       return;
@@ skipping 14 matching lines @@
 }
 
 void URLResponseBodyConsumer::NotifyCompletionIfAppropriate() {
   if (has_been_cancelled_)
     return;
   if (!has_received_completion_ || !has_seen_end_of_data_)
     return;
   // Cancel this instance in order not to notify twice.
   Cancel();
 
   resource_dispatcher_->OnMessageReceived(

[kinuko, 2016/12/27 01:52:21]

No need to be in the same change, but I think this can (should) use
DispatchMessage too.

[yhirano, 2016/12/27 07:32:54]

Done.

       ResourceMsg_RequestComplete(request_id_, completion_status_));
   // |this| may be deleted.
 }
 
 }  // namespace content