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 <string>
+#include <unordered_map>
 #include <utility>
+#include <vector>
 
+#include "base/memory/ptr_util.h"
 #include "blimp/net/blob_channel/blob_channel_sender.h"
 #include "mojo/public/cpp/system/buffer.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::PutBlob(const mojo::String& id,
+void BlobChannelService::GetCachedBlobIds(
+    const BlobChannelService::GetCachedBlobIdsCallback& response_callback) {
+  VLOG(1) << "BlobChannel::GetCachedBlobIds called.";
+  std::unordered_map<std::string, bool> cache_state;
+  for (const auto& next_entry : blob_channel_sender_->GetCachedBlobIds()) {
+    cache_state[next_entry.id] = next_entry.was_delivered;
+  }
+  response_callback.Run(std::move(cache_state));
+}
+
+void BlobChannelService::PutBlob(const std::string& id,
                                  mojo::ScopedSharedBufferHandle data,
                                  uint32_t size) {
   // Map |data| into the address space and copy out its contents.
   if (!data.is_valid()) {
     LOG(ERROR) << "Invalid data handle received from renderer process.";
     return;
   }
 
   if (size > kMaxBlobSizeBytes) {
     LOG(ERROR) << "Blob size too big: " << size;
     return;
   }
 
   mojo::ScopedSharedBufferMapping mapping = data->Map(size);
   CHECK(mapping) << "Failed to mmap region of " << size << " bytes.";
 
   scoped_refptr<BlobData> new_blob(new BlobData);
   new_blob->data.assign(reinterpret_cast<const char*>(mapping.get()), size);
   blob_channel_sender_->PutBlob(id, std::move(new_blob));
 }
 
-void BlobChannelService::DeliverBlob(const mojo::String& id) {
+void BlobChannelService::DeliverBlob(const std::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