Tracing V2: Fully-functional plugin.

components/tracing/test/fake_scattered_buffer.cc

Index: components/tracing/test/fake_scattered_buffer.cc
diff --git a/components/tracing/test/fake_scattered_buffer.cc b/components/tracing/test/fake_scattered_buffer.cc
index 18e16e73f9cc8dccddcb3244404bed036630e096..2523f9a15d479999230d821b72427c02fe2d6d59 100644
--- a/components/tracing/test/fake_scattered_buffer.cc
+++ b/components/tracing/test/fake_scattered_buffer.cc
@@ -29,6 +29,15 @@ std::string FakeScatteredBuffer::GetChunkAsString(int chunk_index) {
   return base::HexEncode(chunks_[chunk_index].get(), chunk_size_);
 }
 
+void FakeScatteredBuffer::GetBytes(size_t start, size_t length, uint8_t* buf) {
+  ASSERT_LE(start + length, chunks_.size() * chunk_size_);
+  for (size_t pos = 0; pos < length; ++pos) {
+    size_t chunk_index = (start + pos) / chunk_size_;
+    size_t chunk_offset = (start + pos) % chunk_size_;
+    buf[pos] = chunks_[chunk_index].get()[chunk_offset];
+  }
+}
+
 std::string FakeScatteredBuffer::GetBytesAsString(size_t start, size_t length) {
   std::string hexstr;
   EXPECT_LE(start + length, chunks_.size() * chunk_size_);

[Primiano Tucci (use gerrit), 2016/08/25 10:31:51]

at this point can you rewrite this in terms of GetBytes + hex serialization?
There feels to be quite some duplication. 
Fine to remove the <OUT OF BOUND> if you have the assert_le.