Create a Lite Page bit for previews and fallback to Lo-Fi

components/data_reduction_proxy/core/common/data_reduction_proxy_params.h

Index: components/data_reduction_proxy/core/common/data_reduction_proxy_params.h
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_params.h b/components/data_reduction_proxy/core/common/data_reduction_proxy_params.h
index c44358df61393b99cff74371d34e8111cd577f85..02b3d9cc19c5da1ea38efff85599a9233defc71b 100644
--- a/components/data_reduction_proxy/core/common/data_reduction_proxy_params.h
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_params.h
@@ -52,6 +52,9 @@ bool IsIncludedInAndroidOnePromoFieldTrial(base::StringPiece build_fingerprint);
 // Returns the name of the Lo-Fi field trial.
 const char* GetLoFiFieldTrialName();
 
+// Returns the name of the Lite Page fallback to Lo-Fi field trial.
+const char* GetLitePageFallbackFieldTrialName();
+
 // Returns the name of the Lo-Fi field trial that configures LoFi flags when it
 // is force enabled through flags.
 const char* GetLoFiFlagFieldTrialName();
@@ -68,6 +71,11 @@ bool IsIncludedInLoFiControlFieldTrial();
 // trial.
 bool IsIncludedInLitePageFieldTrial();
 
+// Returns true if this client is part of the Lite Page fallback to Lo-Fi field
+// trial or if this client has the command line switch to enable lite pages,
+// which should always fallback.
+bool IsLitePageFallbackEnabled();
+
 // Returns true if this client is part of the field trial that should enable
 // server experiments for the data reduction proxy.
 bool IsIncludedInServerExperimentsFieldTrial();
@@ -98,7 +106,8 @@ bool IsLoFiDisabledViaFlags();
 
 // Returns true if this client has the command line switch to enable lite pages.
 // This means a preview should be requested instead of placeholders whenever
-// Lo-Fi mode is on.
+// Lo-Fi mode is on. If Lite Pages are enabled via flags, they will always
+// fallback to Lo-Fi placeholders.
 bool AreLitePagesEnabledViaFlags();
 
 // Returns true if this client has the command line switch to enable forced