Add dawn_wire entrypoints to inject texture in the wire

This allows reserving a texture ID in the client and injecting textures
in the wire, so that the WebGPU control channel can create WebGPU
textures backed by SharedImages in Chromium.

BUG=941543

Change-Id: I1efcfe3dce024bb2d3592f22225407a97b641c1f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/5820
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>

src/include/dawn_wire/WireClient.h

@@ -25,6 +25,12 @@ namespace dawn_wire {
         class Client;
     }
 
+    struct ReservedTexture {
+        DawnTexture texture;
+        uint32_t id;
+        uint32_t generation;
+    };
+
     class DAWN_WIRE_EXPORT WireClient : public CommandHandler {
       public:
         WireClient(CommandSerializer* serializer);
@@ -34,6 +40,8 @@ namespace dawn_wire {
         DawnProcTable GetProcs() const;
         const char* HandleCommands(const char* commands, size_t size) override final;
 
+        ReservedTexture ReserveTexture(DawnDevice device);
+
       private:
         std::unique_ptr<client::Client> mImpl;
     };

src/include/dawn_wire/WireServer.h

@@ -32,6 +32,8 @@ namespace dawn_wire {
 
         const char* HandleCommands(const char* commands, size_t size) override final;
 
+        bool InjectTexture(DawnTexture texture, uint32_t id, uint32_t generation);
+
       private:
         std::unique_ptr<server::Server> mImpl;
     };