Introduce Image loader extension.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index c1864ff73f4db85ff51590a707f512fdef0f48e2..332a1c6f1dfde0404949cf00be46482aaf705764 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1642,6 +1642,9 @@ const char kWaitForMutex[]                  = "wait-for-mutex";
 // Enables overriding the path of file manager extension.
 const char kFileManagerExtensionPath[]      = "filemgr-ext-path";
 
+// Enables overriding the path of image loader extension.
+const char kImageLoaderExtensionPath[]      = "image-loader-ext-path";
+
 // Dumps dependency information about our profile services into a dot file in
 // the profile directory.
 const char kDumpProfileDependencyGraph[]    = "dump-profile-graph";