Add support to previews/ for Server LoFi and LitePages

components/previews/core/previews_experiments.h

Index: components/previews/core/previews_experiments.h
diff --git a/components/previews/core/previews_experiments.h b/components/previews/core/previews_experiments.h
index 7dd7bc2c42c574b296c58ff2391d1e556530a59a..4d37c9b14a2b3e673714f676f5375db533f12bcd 100644
--- a/components/previews/core/previews_experiments.h
+++ b/components/previews/core/previews_experiments.h
@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_PREVIEWS_CORE_PREVIEWS_EXPERIMENTS_H_
 #define COMPONENTS_PREVIEWS_CORE_PREVIEWS_EXPERIMENTS_H_
 
+#include <string>
 #include <utility>
 #include <vector>
 
@@ -49,7 +50,7 @@ base::TimeDelta OfflinePreviewFreshnessDuration();
 
 // The threshold of EffectiveConnectionType above which offline previews should
 // not be served.
-net::EffectiveConnectionType EffectiveConnectionTypeThresholdForOffline();
+net::EffectiveConnectionType EffectiveConnectionTypeThreshold();
 
 // Whether offline previews are enabled.
 bool IsOfflinePreviewsEnabled();
@@ -61,11 +62,11 @@ int OfflinePreviewsVersion();
 bool IsClientLoFiEnabled();
 
 // The blacklist version for Client LoFi previews.

[tbansal1, 2017/05/05 20:34:39]

Is this also the blacklist version for the server lofi?

[RyanSturm, 2017/05/05 20:51:35]

Yes. At that layer, the two optimizations are indistinguishable and clearing
them will use just this param.

-int ClientLoFiVersion();
+int LoFiVersion();
 
 // The threshold of EffectiveConnectionType above which Client LoFi previews
 // should not be served.
-net::EffectiveConnectionType EffectiveConnectionTypeThresholdForClientLoFi();
+net::EffectiveConnectionType EffectiveConnectionTypeThresholdForLoFi();
 
 }  // namespace params
 
@@ -75,12 +76,15 @@ enum class PreviewsType {
   // The user is shown an offline page as a preview.
   OFFLINE = 1,
 
-  // Replace images with placeholders generated on the client.
-  CLIENT_LOFI = 2,
+  // Replace images with placeholders.
+  LOFI = 2,
+
+  // The user is shown a server lite page.
+  LITE_PAGE = 3,
 
   // Insert new enum values here. Keep values sequential to allow looping
   // from NONE+1 to LAST-1.
-  LAST = 3,
+  LAST = 4,
 };
 
 typedef std::vector<std::pair<PreviewsType, int>> PreviewsTypeList;
@@ -88,6 +92,9 @@ typedef std::vector<std::pair<PreviewsType, int>> PreviewsTypeList;
 // Returns true if any client-side previews experiment is active.
 bool IsIncludedInClientSidePreviewsExperimentsFieldTrial();
 
+// Gets the string representation of |type|.
+std::string GetStringNameForType(PreviewsType type);
+
 }  // namespace previews
 
 #endif  // COMPONENTS_PREVIEWS_CORE_PREVIEWS_EXPERIMENTS_H_