Add Mojo IPC for seeding new Renderer with Browser's cached blob state.

blimp/engine/mojo/blob_channel_service.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 "blimp/engine/mojo/blob_channel_service.h"
 
+#include <vector>
+
 #include "blimp/net/blob_channel/blob_channel_sender.h"
 
 namespace blimp {
 namespace engine {
 
 BlobChannelService::BlobChannelService(BlobChannelSender* blob_channel_sender,
                                        mojom::BlobChannelRequest request)
     : binding_(this, std::move(request)),
       blob_channel_sender_(blob_channel_sender) {
   DCHECK(blob_channel_sender_);
 }
 
 BlobChannelService::~BlobChannelService() {}
 
+void BlobChannelService::GetCachedBlobIds(
+    const BlobChannelService::GetCachedBlobIdsCallback& callback) {
+  VLOG(1) << "BlobChannel::GetCachedBlobIds called.";
+
+  // Pass the Mojo representation of the cache state to |callback|.
+  std::vector<BlobChannelSender::CacheStateEntry> cache_state =
+      blob_channel_sender_->GetCachedBlobIds();
+  auto output = mojo::Array<mojom::CacheStateEntryPtr>::New(cache_state.size());
+  for (size_t i = 0; i < cache_state.size(); ++i) {
+    mojom::CacheStateEntryPtr converted(mojom::CacheStateEntry::New());
+    converted->id.Swap(&cache_state[i].id);
+    converted->was_delivered = cache_state[i].was_delivered;

[dcheng, 2016/06/25 00:55:55]

Would it make sense to write a typemap for this rather than marshalling this
manually?

+    output[i] = std::move(converted);
+  }
+  callback.Run(std::move(output));
+}
+
 void BlobChannelService::PutBlob(const mojo::String& id,
                                  const mojo::String& data) {
   blob_channel_sender_->PutBlob(id, new BlobData(data));
 }
 
 void BlobChannelService::DeliverBlob(const mojo::String& id) {
   blob_channel_sender_->DeliverBlob(id);
 }
 
 // static
 void BlobChannelService::Create(
     BlobChannelSender* blob_channel_sender,
     mojo::InterfaceRequest<mojom::BlobChannel> request) {
   // Object lifetime is managed by BlobChannelService's StrongBinding
   // |binding_|.
   new BlobChannelService(blob_channel_sender, std::move(request));
 }
 
 }  // namespace engine
 }  // namespace blimp