Make SpdyHeaderBlock non-copyable.

net/spdy/spdy_header_block.cc

Index: net/spdy/spdy_header_block.cc
diff --git a/net/spdy/spdy_header_block.cc b/net/spdy/spdy_header_block.cc
index 61ca9af575137bca631676c803694354ec424219..09640c83ed6fda3f8e51e95e08030c16921bf468 100644
--- a/net/spdy/spdy_header_block.cc
+++ b/net/spdy/spdy_header_block.cc
@@ -120,13 +120,6 @@ SpdyHeaderBlock::StringPieceProxy::operator StringPiece() const {
 
 SpdyHeaderBlock::SpdyHeaderBlock() : storage_(new Storage) {}
 
-SpdyHeaderBlock::SpdyHeaderBlock(const SpdyHeaderBlock& other)
-    : storage_(new Storage) {
-  for (auto iter : other) {
-    AppendHeader(iter.first, iter.second);
-  }
-}
-
 SpdyHeaderBlock::SpdyHeaderBlock(SpdyHeaderBlock&& other)
     : storage_(std::move(other.storage_)) {
   // |block_| is linked_hash_map, which does not have move constructor.
@@ -135,14 +128,6 @@ SpdyHeaderBlock::SpdyHeaderBlock(SpdyHeaderBlock&& other)
 
 SpdyHeaderBlock::~SpdyHeaderBlock() {}
 
-SpdyHeaderBlock& SpdyHeaderBlock::operator=(const SpdyHeaderBlock& other) {
-  clear();
-  for (auto iter : other) {
-    AppendHeader(iter.first, iter.second);
-  }
-  return *this;
-}
-
 SpdyHeaderBlock& SpdyHeaderBlock::operator=(SpdyHeaderBlock&& other) {
   storage_ = std::move(other.storage_);
   // |block_| is linked_hash_map, which does not have move assignment
@@ -151,6 +136,14 @@ SpdyHeaderBlock& SpdyHeaderBlock::operator=(SpdyHeaderBlock&& other) {
   return *this;
 }
 
+SpdyHeaderBlock SpdyHeaderBlock::Clone() const {
+  SpdyHeaderBlock copy;
+  for (auto iter : *this) {
+    copy.AppendHeader(iter.first, iter.second);
+  }
+  return copy;
+}
+
 bool SpdyHeaderBlock::operator==(const SpdyHeaderBlock& other) const {
   return size() == other.size() && std::equal(begin(), end(), other.begin());
 }