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

blimp/engine/renderer/blob_channel_sender_proxy.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/renderer/blob_channel_sender_proxy.h"
 
 #include "content/public/renderer/render_thread.h"
 #include "services/shell/public/cpp/interface_provider.h"
 
 namespace blimp {
 namespace engine {
 namespace {
 
 mojom::BlobChannelPtr GetConnectedBlobChannel() {
   mojom::BlobChannelPtr blob_channel_ptr;
   content::RenderThread::Get()->GetRemoteInterfaces()->GetInterface(
       &blob_channel_ptr);
   CHECK(blob_channel_ptr) << "Could not connect to BlobChannel Mojo interface.";
   return blob_channel_ptr;
 }
 
 }  // namespace
 
 BlobChannelSenderProxy::BlobChannelSenderProxy()
-    : blob_channel_(GetConnectedBlobChannel()) {}
+    : blob_channel_(GetConnectedBlobChannel()), weak_factory_(this) {
+  // TODO(kmarshall): Switch to observer push model (vs. the current pull model)
+  // once cache invalidations are introduced.

[Wez, 2016/07/01 00:30:20]

nit: Either refer to the bug for this TODO, or remove it, I think - no need for
a reminder in the code, as such, I don't think?

[nyquist, 2016/07/15 22:13:46]

Yeah, and if there is no bug for it, just file one. Nowadays we should hopefully
also be able to do this by ourselves instead of waiting for fancy functionality
from Skia, pending the big change in how the compositor protocol works.

[Kevin M, 2016/07/18 16:58:16]

Done.

[Kevin M, 2016/07/18 16:58:16]

Done.

+  blob_channel_->GetCachedBlobIds(
+      base::Bind(&BlobChannelSenderProxy::OnGetCacheStateComplete,
+                 weak_factory_.GetWeakPtr()));
+}
 
 BlobChannelSenderProxy::~BlobChannelSenderProxy() {}
 
 bool BlobChannelSenderProxy::IsInEngineCache(const std::string& id) const {
   return replication_state_.find(id) != replication_state_.end();
 }
 
 bool BlobChannelSenderProxy::IsInClientCache(const std::string& id) const {
   return replication_state_.find(id)->second;
 }
 
 void BlobChannelSenderProxy::PutBlob(const BlobId& id, BlobDataPtr data) {
   DCHECK(!IsInEngineCache(id));
 
   replication_state_[id] = false;
   blob_channel_->PutBlob(id, data->data);
 }
 
 void BlobChannelSenderProxy::DeliverBlob(const std::string& id) {
   DCHECK(!IsInClientCache(id));
 
   // We assume that the client will have the blob if we push it.
   // TODO(kmarshall): Revisit this assumption when asynchronous blob transport
   // is supported.
   replication_state_[id] = true;
 
   blob_channel_->DeliverBlob(id);
 }
 
+std::vector<BlobChannelSender::CacheStateEntry>
+BlobChannelSenderProxy::GetCachedBlobIds() const {
+  NOTREACHED();
+  return std::vector<BlobChannelSender::CacheStateEntry>();
+}
+
+void BlobChannelSenderProxy::OnGetCacheStateComplete(
+  mojo::Map<mojo::String, bool> cache_state
+) {

[Wez, 2016/07/01 00:30:21]

nit: This is very strange looking line-wrapping! Is this what git cl format does
now?

[Kevin M, 2016/07/18 16:58:16]

Re-ran git cl format, formatting is saner. I must've neglected to run it before
uploading the last patch.

+  VLOG(1) << "Received cache state from browser (" << cache_state.size()
+          << " items)";
+  replication_state_.clear();
+  for (const auto& next_item : cache_state) {
+    replication_state_[next_item.first] = next_item.second;
+  }
+}
+
 }  // namespace engine
 }  // namespace blimp