Add a fuzzer for the wire server and Dawn frontend

BUG=dawn:34

Change-Id: Ia82b52276c91ed3bd1a246548115e75ba0ede7f2
Reviewed-on: https://dawn-review.googlesource.com/c/2302
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Dan Sinclair <dsinclair@google.com>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>

BUILD.gn

@@ -1030,4 +1030,18 @@ if (build_with_chromium) {
       ":dawn_spirv_cross_fuzzer_common",
     ]
   }
+
+  fuzzer_test("dawn_wire_server_and_frontend_fuzzer") {
+    sources = [
+      "src/fuzzers/DawnWireServerAndFrontendFuzzer.cpp",
+    ]
+
+    deps = [
+      ":libdawn",
+      ":libdawn_native",
+      ":libdawn_wire",
+    ]
+
+    additional_configs = [ ":dawn_shared_library_public" ]
+  }
 }

src/fuzzers/DawnWireServerAndFrontendFuzzer.cpp

@@ -0,0 +1,51 @@
+// 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.
+
+#include "dawn/dawncpp.h"
+#include "dawn_native/DawnNative.h"
+#include "dawn_native/NullBackend.h"
+#include "dawn_wire/Wire.h"
+
+#include <vector>
+
+class DevNull : public dawn_wire::CommandSerializer {
+  public:
+    void* GetCmdSpace(size_t size) override {
+        if (size > buf.size()) {
+            buf.resize(size);
+        }
+        return buf.data();
+    }
+    bool Flush() override {
+        return true;
+    };
+
+  private:
+    std::vector<char> buf;
+};
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    dawnProcTable procs = dawn_native::GetProcs();
+    dawnSetProcs(&procs);
+
+    dawn::Device nullDevice = dawn_native::null::CreateDevice();
+
+    DevNull devNull;
+    std::unique_ptr<dawn_wire::CommandHandler> wireServer(
+        dawn_wire::NewServerCommandHandler(nullDevice.Get(), procs, &devNull));
+
+    wireServer->HandleCommands(reinterpret_cast<const char*>(data), size);
+
+    return 0;
+}