HPACK optimal Huffman code instrumentation and UMA collection.

net/spdy/hpack_encoder_test.cc

Index: net/spdy/hpack_encoder_test.cc
diff --git a/net/spdy/hpack_encoder_test.cc b/net/spdy/hpack_encoder_test.cc
index 316952edd0dcbd4fe4e91f628b5e3b0cb59ffc46..da9bff5a7c4a5444ad4aea29e2e39f2d121ca9de 100644
--- a/net/spdy/hpack_encoder_test.cc
+++ b/net/spdy/hpack_encoder_test.cc
@@ -23,6 +23,9 @@ class HpackEncoderPeer {
   explicit HpackEncoderPeer(HpackEncoder* encoder)
       : encoder_(encoder) {}
 
+  void UpdateCharacterCounts(StringPiece str) {
+    encoder_->UpdateCharacterCounts(str);
+  }
   void set_max_string_literal_size(uint32 size) {
     encoder_->max_string_literal_size_ = size;
   }
@@ -112,6 +115,30 @@ TEST(HpackEncoderTest, HeaderTooLarge) {
   EXPECT_FALSE(encoder.EncodeHeaderSet(header_set, &encoded_header_set));
 }
 
+TEST(HpackEncoderTest, UpdateCharacterCounts) {
+  HpackEncoder encoder;
+  test::HpackEncoderPeer peer(&encoder);
+
+  std::vector<size_t> counts(256, 0);
+  size_t total_counts = 0;
+  encoder.SetCharCountsStorage(&counts, &total_counts);
+
+  char kTestString[] = "foo\0\1\xff""boo";
+  peer.UpdateCharacterCounts(
+      StringPiece(kTestString, arraysize(kTestString) - 1));
+
+  std::vector<size_t> expect(256, 0);
+  expect[static_cast<uint8>('f')] = 1;
+  expect[static_cast<uint8>('o')] = 4;
+  expect[static_cast<uint8>('\0')] = 1;
+  expect[static_cast<uint8>('\1')] = 1;
+  expect[static_cast<uint8>('\xff')] = 1;
+  expect[static_cast<uint8>('b')] = 1;
+
+  EXPECT_EQ(expect, counts);
+  EXPECT_EQ(9u, total_counts);
+}
+
 }  // namespace
 
 }  // namespace net