Add a switch to Chromium to enable/disable 'image/webp' accept header.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 22fe278c36f7baac34a39fc2173afaa636646eda..baa49e272a514620fcb91cf0c05f128116a4cac6 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1351,6 +1351,13 @@ const Experiment kExperiments[] = {
     kOsLinux | kOsCrOS | kOsAndroid,
     SINGLE_VALUE_TYPE(switches::kEnableTcpFastOpen)
   },
+  {
+    "enable-webp-in-accept-header",
+    IDS_FLAGS_ENABLE_WEBP_IN_ACCEPT_HEADER_NAME,
+    IDS_FLAGS_ENABLE_WEBP_IN_ACCEPT_HEADER_DESCRIPTION,
+    kOsAll,
+    SINGLE_VALUE_TYPE(switches::kEnableWebPInAcceptHeader)
+  },
 };
 
 const Experiment* experiments = kExperiments;