Add filtering logic for client-side variations.

chrome/browser/metrics/variations_service.h

Index: chrome/browser/metrics/variations_service.h
diff --git a/chrome/browser/metrics/variations_service.h b/chrome/browser/metrics/variations_service.h
index be9323d1d8a92f7c7933dc5d67206c48092e7944..d3ff997ebcef82bd192c7cbcee05cfc75724ca90 100644
--- a/chrome/browser/metrics/variations_service.h
+++ b/chrome/browser/metrics/variations_service.h
@@ -6,9 +6,15 @@
 #define CHROME_BROWSER_METRICS_VARIATIONS_SERVICE_H_
 #pragma once
 
+#include <string>
+
 #include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
+#include "base/time.h"
 #include "base/memory/scoped_ptr.h"
+#include "chrome/browser/metrics/proto/study.pb.h"
 #include "chrome/browser/metrics/proto/trials_seed.pb.h"
+#include "chrome/common/chrome_version_info.h"
 #include "content/public/common/url_fetcher_delegate.h"
 
 template <typename T> struct DefaultSingletonTraits;
@@ -40,6 +46,11 @@ class VariationsService : public content::URLFetcherDelegate {
  private:
   friend struct DefaultSingletonTraits<VariationsService>;
 
+  FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyChannel);
+  FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyVersion);
+  FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyVersionWildcards);
+  FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyDate);
+
   VariationsService();
 
   // Store the given seed data to the given local prefs. Note that |seed_data|
@@ -48,6 +59,22 @@ class VariationsService : public content::URLFetcherDelegate {
   // fails, the |local_prefs| is left as is.
   void StoreSeedData(const std::string& seed_data, PrefService* local_prefs);
 
+  // Returns whether |study| should be added to the local field trials list
+  // according to its restriction parameters.
+  static bool ShouldAddStudy(const chrome_variations::Study& study);
+
+  // Checks whether |study| is applicable for the given |channel|.
+  static bool CheckStudyChannel(const chrome_variations::Study& study,
+                                chrome::VersionInfo::Channel channel);
+
+  // Checks whether |study| is applicable for the given version string.
+  static bool CheckStudyVersion(const chrome_variations::Study& study,
+                                const std::string& version_string);
+
+  // Checks whether |study| is applicable for the given date/time.
+  static bool CheckStudyDate(const chrome_variations::Study& study,
+                             const base::Time& date_time);
+
   // Contains the current seed request. Will only have a value while a request
   // is pending, and will be reset by |OnURLFetchComplete|.
   scoped_ptr<content::URLFetcher> pending_seed_request_;