Add support for Omaha cohorts to the component updater.

components/update_client/update_checker.cc

 // Copyright 2014 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.
 
 #include "components/update_client/update_checker.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
@@ skipping 73 matching lines @@
     base::StringAppendF(&app, "appid=\"%s\" version=\"%s\"", item->id.c_str(),
                         item->component.version.GetString().c_str());
     if (!brand.empty())
       base::StringAppendF(&app, " brand=\"%s\"", brand.c_str());
     if (item->on_demand)
       base::StringAppendF(&app, " installsource=\"ondemand\"");
     for (const auto& attr : installer_attributes) {
       base::StringAppendF(&app, " %s=\"%s\"", attr.first.c_str(),
                           attr.second.c_str());
     }
+    const std::string& cohort = metadata->GetCohort(item->id);

[Sorin Jianu, 2016/08/18 21:15:15]

This is a small deal and mostly a matter of personal preference. The code is
correct as it is written. However, I avoid references to temporaries and I
prefer to use named local variables in cases like this. The code is as efficient
as the code with references (the temporary is moved into the local variable in
one case, and in the other case the temporary is still created and needs to live
until the end of the scope for the reference).
Why the fuss? Depending what the code does after the call site, I still could
end up with dangling references, so personally, I am always suspicious when I
see the reference to something that is local.

[waffles, 2016/08/18 22:29:23]

Done.

+    const std::string& cohort_name = metadata->GetCohortName(item->id);
+    const std::string& cohort_hint = metadata->GetCohortHint(item->id);
+    if (!cohort.empty())
+      base::StringAppendF(&app, " cohort=\"%s\"", cohort.c_str());
+    if (!cohort_name.empty())
+      base::StringAppendF(&app, " cohortname=\"%s\"", cohort_name.c_str());
+    if (!cohort_hint.empty())
+      base::StringAppendF(&app, " cohorthint=\"%s\"", cohort_hint.c_str());
     base::StringAppendF(&app, ">");
 
     base::StringAppendF(&app, "<updatecheck");
     if (item->component.supports_group_policy_enable_component_updates &&
         !enabled_component_updates) {
       base::StringAppendF(&app, " updatedisabled=\"true\"");
     }
     base::StringAppendF(&app, "/>");
 
     base::StringAppendF(&app, "<ping rd=\"%d\" ping_freshness=\"%s\" />",
@@ skipping 92 matching lines @@
     const std::string& response,
     int retry_after_sec) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (!error) {
     UpdateResponse update_response;
     if (update_response.Parse(response)) {
       int daynum = update_response.results().daystart_elapsed_days;
       if (daynum != UpdateResponse::kNoDaystart)
         metadata_->SetDateLastRollCall(*ids_checked, daynum);
+      for (auto result : update_response.results().list) {
+        if (result.set_cohort)
+          metadata_->SetCohort(result.extension_id, result.cohort);
+        if (result.set_cohort_hint)
+          metadata_->SetCohortHint(result.extension_id, result.cohort_hint);
+        if (result.set_cohort_name)
+          metadata_->SetCohortName(result.extension_id, result.cohort_name);
+      }
       base::ThreadTaskRunnerHandle::Get()->PostTask(
           FROM_HERE, base::Bind(update_check_callback_, error,
                                 update_response.results(), retry_after_sec));
       return;
     }
 
     error = -1;
     VLOG(1) << "Parse failed " << update_response.errors();
   }
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(update_check_callback_, error,
                             UpdateResponse::Results(), retry_after_sec));
 }
 
 }  // namespace
 
 std::unique_ptr<UpdateChecker> UpdateChecker::Create(
     const scoped_refptr<Configurator>& config,
     PersistedData* persistent) {
   return std::unique_ptr<UpdateChecker>(
       new UpdateCheckerImpl(config, persistent));
 }
 
 }  // namespace update_client