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

sync/internal_api/public/http_bridge.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SYNC_INTERNAL_API_PUBLIC_HTTP_BRIDGE_H_
 #define SYNC_INTERNAL_API_PUBLIC_HTTP_BRIDGE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/timer/timer.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/cancelation_observer.h"
 #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;
 
 namespace base {
 class MessageLoop;
 }
 
 namespace net {
 class HttpResponseHeaders;
 class HttpUserAgentSettings;
 class URLFetcher;
 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.
 // Provides a way for the sync backend to use Chromium directly for HTTP
 // requests rather than depending on a third party provider (e.g libcurl).
 // This is a one-time use bridge. Create one for each request you want to make.
 // It is RefCountedThreadSafe because it can PostTask to the io loop, and thus
 // needs to stick around across context switches, etc.
 class SYNC_EXPORT_PRIVATE HttpBridge
     : public base::RefCountedThreadSafe<HttpBridge>,
@@ skipping 163 matching lines @@
   NetworkTimeUpdateCallback network_time_update_callback_;
 
   CancelationSignal* const cancelation_signal_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpBridgeFactory);
 };
 
 }  //  namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_HTTP_BRIDGE_H_