Use the Previews Black List for server previews

components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc

Index: components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc b/components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc
index 5e3cd12f13414510cf584f57c1cb057cd304e8ac..a866f12df2a32f4e2f60fc594b7edd70f4dad757 100644
--- a/components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc
@@ -45,6 +45,9 @@ const char kLitePageFallbackFieldTrial[] =
     "DataCompressionProxyLitePageFallback";
 const char kLoFiFlagFieldTrial[] = "DataCompressionProxyLoFiFlag";
 
+const char kBlacklistTransitionFieldTrial[] =
+    "DataReductionProxyPreviewsBlacklistTransition";

[megjablon, 2017/05/09 19:58:33]

s/Blacklist/BlackList 
Please check that this consistent everywhere.

[RyanSturm, 2017/05/09 22:35:19]

Done.

+
 const char kTrustedSpdyProxyFieldTrialName[] = "DataReductionTrustedSpdyProxy";
 
 // Default URL for retrieving the Data Reduction Proxy configuration.
@@ -271,6 +274,12 @@ bool IsConfigClientEnabled() {
       kDisabled, base::CompareCase::SENSITIVE);
 }
 
+bool IsBlackListEnabledForServerPreviews() {
+  return base::StartsWith(
+      base::FieldTrialList::FindFullName(kBlacklistTransitionFieldTrial),
+      kEnabled, base::CompareCase::SENSITIVE);
+}
+
 GURL GetConfigServiceURL() {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   std::string url;