[OBSOLETE] tracing v2: introduce TraceBufferWriter

components/tracing/core/trace_ring_buffer_unittest.cc

Index: components/tracing/core/trace_ring_buffer_unittest.cc
diff --git a/components/tracing/core/trace_ring_buffer_unittest.cc b/components/tracing/core/trace_ring_buffer_unittest.cc
index 0738f82516dbdbb12e464f255e26fd1aa3465825..0881635beca1d9fdf274e8f9d5f5d1fab3534377 100644
--- a/components/tracing/core/trace_ring_buffer_unittest.cc
+++ b/components/tracing/core/trace_ring_buffer_unittest.cc
@@ -26,14 +26,16 @@ TEST(TraceRingBufferTest, BasicChunkWrapping) {
   uint8_t* last_chunk_end = nullptr;
   // Fill the buffer twice to test wrapping logic.
   for (uint32_t i = 0; i < kNumChunks * 2; ++i) {
-    TraceRingBuffer::Chunk* chunk = ring_buffer.TakeChunk();
+    TraceRingBuffer::Chunk* chunk = ring_buffer.TakeChunk(42 /* owner */);
     ASSERT_NE(nullptr, chunk);
+    EXPECT_EQ(42u, chunk->owner());
     const uint32_t chunk_idx = i % kNumChunks;
     EXPECT_EQ(chunk_idx == 0 ? storage.get() : last_chunk_end, chunk->begin());
     const uint32_t kPayloadSize = (chunk_idx + 1) * 8;
     memset(chunk->payload(), static_cast<int>(chunk_idx + 1), kPayloadSize);
     last_chunk_end = chunk->end();
-    ring_buffer.ReturnChunk(chunk, /* used_size = */ kPayloadSize);
+    chunk->set_used_size(kPayloadSize);
+    ring_buffer.ReturnChunk(chunk);
   }
 
   // Now scrape the |storage| buffer and check its contents.
@@ -52,14 +54,14 @@ TEST(TraceRingBufferTest, ChunkBankrupcyDoesNotCrash) {
   std::unique_ptr<uint8_t[]> storage(new uint8_t[kBufferSize]);
   TraceRingBuffer ring_buffer(storage.get(), kBufferSize);
 
-  TraceRingBuffer::Chunk* chunk1 = ring_buffer.TakeChunk();
+  TraceRingBuffer::Chunk* chunk1 = ring_buffer.TakeChunk(1);
   ASSERT_NE(nullptr, chunk1);
 
-  TraceRingBuffer::Chunk* chunk2 = ring_buffer.TakeChunk();
+  TraceRingBuffer::Chunk* chunk2 = ring_buffer.TakeChunk(1);
   ASSERT_NE(nullptr, chunk2);
 
   for (int i = 0; i < 3; ++i) {
-    TraceRingBuffer::Chunk* bankrupcy_chunk = ring_buffer.TakeChunk();
+    TraceRingBuffer::Chunk* bankrupcy_chunk = ring_buffer.TakeChunk(1);
     ASSERT_NE(nullptr, bankrupcy_chunk);
     ASSERT_FALSE(overlap(bankrupcy_chunk->begin(), bankrupcy_chunk->end(),
                          storage.get(), storage.get() + kBufferSize));
@@ -69,8 +71,9 @@ TEST(TraceRingBufferTest, ChunkBankrupcyDoesNotCrash) {
   }
 
   // Return a chunk and check that the ring buffer is not bankrupt anymore.
-  ring_buffer.ReturnChunk(chunk2, 42);
-  TraceRingBuffer::Chunk* chunk = ring_buffer.TakeChunk();
+  chunk2->set_used_size(42);
+  ring_buffer.ReturnChunk(chunk2);
+  TraceRingBuffer::Chunk* chunk = ring_buffer.TakeChunk(1);
   ASSERT_NE(nullptr, chunk);
   ASSERT_TRUE(overlap(chunk->begin(), chunk->end(), storage.get(),
                       storage.get() + kBufferSize));