Make dawn_wire a shared library

Also moves the TerribleCommandBuffer to utils:: because it isn't part of
the implementation of the wire, renames dawn::wire to dawn_wire, moves
src/wire to src/dawn_wire and puts the interface of dawn_wire in
src/include/dawn_wire.

src/include/dawn_wire/Wire.h

@@ -0,0 +1,47 @@
+// Copyright 2017 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef DAWNWIRE_WIRE_H_
+#define DAWNWIRE_WIRE_H_
+
+#include <cstdint>
+
+#include "dawn/dawn.h"
+#include "dawn_wire/dawn_wire_export.h"
+
+namespace dawn_wire {
+
+    class DAWN_WIRE_EXPORT CommandSerializer {
+      public:
+        virtual ~CommandSerializer() = default;
+        virtual void* GetCmdSpace(size_t size) = 0;
+        virtual bool Flush() = 0;
+    };
+
+    class DAWN_WIRE_EXPORT CommandHandler {
+      public:
+        virtual ~CommandHandler() = default;
+        virtual const char* HandleCommands(const char* commands, size_t size) = 0;
+    };
+
+    DAWN_WIRE_EXPORT CommandHandler* NewClientDevice(dawnProcTable* procs,
+                                                     dawnDevice* device,
+                                                     CommandSerializer* serializer);
+    DAWN_WIRE_EXPORT CommandHandler* NewServerCommandHandler(dawnDevice device,
+                                                             const dawnProcTable& procs,
+                                                             CommandSerializer* serializer);
+
+}  // namespace dawn_wire
+
+#endif  // DAWNWIRE_WIRE_H_

src/include/dawn_wire/dawn_wire_export.h

@@ -0,0 +1,32 @@
+// Copyright 2018 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef DAWNWIRE_EXPORT_H_
+#define DAWNWIRE_EXPORT_H_
+
+#if defined(WIN32)
+#    if defined(DAWN_WIRE_IMPLEMENTATION)
+#        define DAWN_WIRE_EXPORT __declspec(dllexport)
+#    else
+#        define DAWN_WIRE_EXPORT __declspec(dllimport)
+#    endif
+#else
+#    if defined(DAWN_WIRE_IMPLEMENTATION)
+#        define DAWN_WIRE_EXPORT __attribute__((visibility("default")))
+#    else
+#        define DAWN_WIRE_EXPORT
+#    endif
+#endif
+
+#endif  // DAWNWIRE_EXPORT_H_