Replace the existing SpdyHeaderBlock typedef with a class.

net/spdy/spdy_test_utils.h

Index: net/spdy/spdy_test_utils.h
diff --git a/net/spdy/spdy_test_utils.h b/net/spdy/spdy_test_utils.h
index ee3d6582fb86c0318abd2042098d180f0971bdc2..e052a3f0dc3e1fb05661c5e26217edcb5ef43ff4 100644
--- a/net/spdy/spdy_test_utils.h
+++ b/net/spdy/spdy_test_utils.h
@@ -9,6 +9,7 @@
 
 #include <string>
 
+#include "net/spdy/spdy_header_block.h"
 #include "net/spdy/spdy_protocol.h"
 
 namespace net {
@@ -16,6 +17,11 @@ namespace net {
 class HashValue;
 class TransportSecurityState;
 
+inline bool operator==(StringPiece x,
+                       const SpdyHeaderBlock::StringPieceProxy& y) {
+  return x == y.operator StringPiece();
+}

[Ryan Hamilton, 2015/09/24 17:54:06]

I wonder if it might just be easier to have a method like
bool CheckHeaderBlockHasValue(SpdyHeaderBlock block, StringPiece key,
StringPiece value);

Operator overloading is often a bad idea.

[Bence, 2015/09/24 21:14:51]

I would like to ask you to reconsider.  This operator allows smooth
EXPECT_EQ("GET", headers["method"])
statements in spdy_header_block_test, spdy_framer_test, spdy_http_utils_test,
and tools/flip_server/spdy_interface_test (see Patch Set 17).  Many of them. 
This reads much more easily than either
EXPECT_EQ("GET", static_cast<StringPiece>(headers["method"]))
or
EXPECT_TRUE(HeaderValueEquals(headers, "method", "GET"))
with the latter having the further disadvantage that on failure it does not
print the mismatching value.

Out of curiosity, why is overloading a bad idea, what are the possible pitfalls?
 Maybe there is a way to mitigate them.

By the way I was looking at testing/gtest/src/gtest.cc to see if there is any
helper comparison function that can be overloaded (like there is an overloadable
pretty print function), but it does not seem like the case.

[Ryan Hamilton, 2015/09/24 22:25:55]

*grumble* :> Ok, fair enough. In particular your point about not printing the
mismatch convinces me.
In general:

https://engdoc.corp.google.com/eng/doc/devguide/cpp/styleguide.shtml?cl=head#...

But what you've done is definitely on the sane side of the fence, I'm just
basically allergic. But your point is compelling.

+
 namespace test {
 
 std::string HexDumpWithMarks(const unsigned char* data, int length,