Adds a new operator to SpdyHeaderBlock::ValueProxy, allowing it to be compared with SpdyStringPiece.

gfe-relnote: n/a (new code, only used in tests)
PiperOrigin-RevId: 285846905
Change-Id: I5273fbe19b4cb9c7778f98fd53e2fb7d003881d5
diff --git a/spdy/core/spdy_header_block.cc b/spdy/core/spdy_header_block.cc
index 609f6d7..c87bfff 100644
--- a/spdy/core/spdy_header_block.cc
+++ b/spdy/core/spdy_header_block.cc
@@ -140,7 +140,7 @@
 }
 
 SpdyHeaderBlock::ValueProxy& SpdyHeaderBlock::ValueProxy::operator=(
-    const SpdyStringPiece value) {
+    SpdyStringPiece value) {
   *spdy_header_block_value_size_ += value.size();
   SpdyHeaderStorage* storage = &block_->storage_;
   if (lookup_result_ == block_->map_.end()) {
@@ -158,6 +158,14 @@
   return *this;
 }
 
+bool SpdyHeaderBlock::ValueProxy::operator==(SpdyStringPiece value) const {
+  if (lookup_result_ == block_->map_.end()) {
+    return false;
+  } else {
+    return value == lookup_result_->second.value();
+  }
+}
+
 std::string SpdyHeaderBlock::ValueProxy::as_string() const {
   if (lookup_result_ == block_->map_.end()) {
     return "";