[Sync] Finch Experiment : Enable compression between sync client and server

sync/internal_api/public/http_bridge.h

Index: sync/internal_api/public/http_bridge.h
diff --git a/sync/internal_api/public/http_bridge.h b/sync/internal_api/public/http_bridge.h
index 36704e2a1bd5040db54b1f3a9f551d717c671758..ba9b9a6be9e12471594261878810e2e9035017a6 100644
--- a/sync/internal_api/public/http_bridge.h
+++ b/sync/internal_api/public/http_bridge.h
@@ -22,6 +22,7 @@
 #include "sync/internal_api/public/http_post_provider_factory.h"
 #include "sync/internal_api/public/http_post_provider_interface.h"
 #include "sync/internal_api/public/network_time_update_callback.h"
+#include "third_party/zlib/zlib.h"
 #include "url/gurl.h"
 
 class HttpBridgeTest;
@@ -39,6 +40,17 @@ class URLRequestJobFactory;
 
 namespace syncer {
 
+// TODO: This two functions are copied from

[Nicolas Zea, 2015/07/30 19:59:44]

TODO's should have an owner, and ideally reference a bug. So: TODO(gangwu):
crbug.com/XXXX ....

[Gang Wu, 2015/07/31 00:39:45]

Done.

+// components/metrics/compression_utils.h, we copied them because if we
+// reference them, we will get cycle dependency warning. so once the functions

[Nicolas Zea, 2015/07/30 19:59:44]

nit: ". so once the" -> ". Once the"

[Gang Wu, 2015/07/31 00:39:45]

Done.

+// have been moved from //component to //base, we can remove the following
+// functions.
+SYNC_EXPORT_PRIVATE bool GzipCompress(const std::string& input,
+                                      std::string* output);
+
+SYNC_EXPORT_PRIVATE bool GzipUncompress(const std::string& input,

[Nicolas Zea, 2015/07/30 19:59:44]

Given this isn't actually used in HttpBridge, and only in tests, I'd rather it
live in the test itself (with the same comment about the TODO above)

[Gang Wu, 2015/07/31 00:39:45]

Done.

+                                        std::string* output);
+
 class CancelationSignal;
 
 // A bridge between the syncer and Chromium HTTP layers.