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

blimp/engine/renderer/blob_channel_sender_proxy.h

Index: blimp/engine/renderer/blob_channel_sender_proxy.h
diff --git a/blimp/engine/renderer/blob_channel_sender_proxy.h b/blimp/engine/renderer/blob_channel_sender_proxy.h
index e219ef06c35e7ff5fda51bed6f00343a4bd8ceb7..2a7b7e1331f8c057630d7b6b492390cbcb3b91a5 100644
--- a/blimp/engine/renderer/blob_channel_sender_proxy.h
+++ b/blimp/engine/renderer/blob_channel_sender_proxy.h
@@ -7,8 +7,10 @@
 
 #include <memory>
 #include <string>
+#include <vector>
 
 #include "base/containers/hash_tables.h"
+#include "base/memory/weak_ptr.h"
 #include "blimp/common/blimp_common_export.h"
 #include "blimp/engine/mojo/blob_channel.mojom.h"
 #include "blimp/net/blob_channel/blob_channel_sender.h"
@@ -30,10 +32,13 @@ class BLIMP_COMMON_EXPORT BlobChannelSenderProxy : public BlobChannelSender {
   bool IsInClientCache(const std::string& id) const;
 
   // BlobChannelSender implementation.
+  std::vector<CacheState> GetCacheState() const override;
   void PutBlob(const BlobId& id, BlobDataPtr data) override;
   void DeliverBlob(const BlobId& id) override;
 
  private:
+  void GotCacheState(mojo::Array<mojom::CacheStateEntryPtr> cache_state);

[Wez, 2016/06/21 00:33:33]

nit: OnGetCacheStateComplete()?

[Kevin M, 2016/06/21 21:23:52]

Done.

+
   // BlobChannel Mojo IPC stub, used for delivering blobs to the browser
   // process.
   mojom::BlobChannelPtr blob_channel_;
@@ -43,6 +48,8 @@ class BLIMP_COMMON_EXPORT BlobChannelSenderProxy : public BlobChannelSender {
   // image encoding and transferral if the content is already in the system.
   base::hash_map<std::string, bool> replication_state_;
 
+  base::WeakPtrFactory<BlobChannelSenderProxy> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(BlobChannelSenderProxy);
 };