Improve error handling of the transport security state generator.

net/tools/transport_security_state_generator/trie/trie_bit_buffer.h

Index: net/tools/transport_security_state_generator/trie/trie_bit_buffer.h
diff --git a/net/tools/transport_security_state_generator/trie/trie_bit_buffer.h b/net/tools/transport_security_state_generator/trie/trie_bit_buffer.h
index f49ffb116bb72431c840a0cd14a9d4d23679f078..0debacbd7881ea2f21704ba7e4dfaab9e6814cc1 100644
--- a/net/tools/transport_security_state_generator/trie/trie_bit_buffer.h
+++ b/net/tools/transport_security_state_generator/trie/trie_bit_buffer.h
@@ -9,6 +9,7 @@
 
 #include <vector>
 
+#include "base/macros.h"
 #include "net/tools/transport_security_state_generator/huffman/huffman_builder.h"
 
 namespace net {
@@ -40,8 +41,8 @@ class TrieBitBuffer {
 
   // Writes the character in |byte| to the buffer using its Huffman
   // representation in |table|. Optionally tracks usage of the character in
-  // |*huffman_builder|.
-  void WriteChar(uint8_t byte,
+  // |*huffman_builder|. Returns false when |byte| is not found in |table|.
+  bool WriteChar(uint8_t byte,
                  const HuffmanRepresentationTable& table,
                  HuffmanBuilder* huffman_builder);
 
@@ -49,8 +50,8 @@ class TrieBitBuffer {
   // at before the buffer was written to it.
   uint32_t WriteToBitWriter(BitWriter* writer);
 
-  // Appends the buffered bits in |current_byte_| to |elements_|. Empty bits
-  // are filled with zero's.
+  // Appends the buffered bits in |current_byte_| to |elements_|. No padding
+  // will occur.

[Ryan Sleevi, 2017/02/14 20:53:17]

Why this semantic change of the API?

[martijnc, 2017/02/15 22:07:59]

The old comment was incorrect. The API already behaves this way.

   void Flush();
 
  private:
@@ -76,6 +77,8 @@ class TrieBitBuffer {
   uint32_t used_ = 0;
 
   std::vector<BitsOrPosition> elements_;
+
+  DISALLOW_COPY_AND_ASSIGN(TrieBitBuffer);
 };
 
 }  // namespace transport_security_state