Add an about:flag to enable client-side LoFi

chrome/browser/flag_descriptions.cc

Index: chrome/browser/flag_descriptions.cc
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 2d865dfe2d36505e861f9f6f2c56ff312d8eaf44..342f9a4caf284c430c242a77b7f592ee4649aa28 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -1213,6 +1213,11 @@ const char kEnableOfflinePreviewsName[] = "Offline Page Previews";
 const char kEnableOfflinePreviewsDescription[] =
     "Enable showing offline page previews on slow networks.";
 
+const char kEnableClientLoFiName[] = "Client-side Lo-Fi previews";
+
+const char kEnableClientLoFiDescription[] =
+    "Enable showing low fidelity images on some pages on slow networks.";
+
 #endif  // defined(OS_ANDROID)
 
 const char kLcdTextName[] = "LCD text antialiasing";