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.
diff --git a/src/utils/TerribleCommandBuffer.cpp b/src/utils/TerribleCommandBuffer.cpp
new file mode 100644
index 0000000..77f86ec
--- /dev/null
+++ b/src/utils/TerribleCommandBuffer.cpp
@@ -0,0 +1,60 @@
+// 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.
+
+#include "utils/TerribleCommandBuffer.h"
+
+#include "common/Assert.h"
+
+namespace utils {
+
+    TerribleCommandBuffer::TerribleCommandBuffer() {
+    }
+
+    TerribleCommandBuffer::TerribleCommandBuffer(dawn_wire::CommandHandler* handler)
+        : mHandler(handler) {
+    }
+
+    void TerribleCommandBuffer::SetHandler(dawn_wire::CommandHandler* handler) {
+        mHandler = handler;
+    }
+
+    void* TerribleCommandBuffer::GetCmdSpace(size_t size) {
+        // TODO(kainino@chromium.org): Should we early-out if size is 0?
+        //   (Here and/or in the caller?) It might be good to make the wire receiver get a nullptr
+        //   instead of pointer to zero-sized allocation in mBuffer.
+
+        if (size > sizeof(mBuffer)) {
+            return nullptr;
+        }
+
+        char* result = &mBuffer[mOffset];
+        mOffset += size;
+
+        if (mOffset > sizeof(mBuffer)) {
+            if (!Flush()) {
+                return nullptr;
+            }
+            return GetCmdSpace(size);
+        }
+
+        return result;
+    }
+
+    bool TerribleCommandBuffer::Flush() {
+        bool success = mHandler->HandleCommands(mBuffer, mOffset) != nullptr;
+        mOffset = 0;
+        return success;
+    }
+
+}  // namespace utils