tracing v2: Introduce TraceBufferWriter

components/tracing/core/proto_utils.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_TRACING_CORE_PROTO_UTILS_H_
 #define COMPONENTS_TRACING_CORE_PROTO_UTILS_H_
 
 #include <inttypes.h>
 
 #include <type_traits>
@@ skipping 77 matching lines @@
 template <size_t LENGTH>
 void WriteRedundantVarIntU32(uint32_t value, uint8_t* buf) {
   for (size_t i = 0; i < LENGTH; ++i) {
     const uint8_t msb = (i < LENGTH - 1) ? 0x80 : 0;
     buf[i] = static_cast<uint8_t>((value & 0x7F) | msb);
     value >>= 7;
   }
   DCHECK_EQ(0u, value) << "Buffer too short to encode the given value";
 }
 
+template <uint32_t field_id>
+void StaticAssertSingleBytePreamble() {
+  static_assert(field_id < 16,
+                "Proto field id too big to fit in a single byte preamble");
+};
+
 }  // namespace proto
 }  // namespace v2
 }  // namespace tracing
 
 #endif  // COMPONENTS_TRACING_CORE_PROTO_UTILS_H_