tools: Local tests for the speculative prefetch predictor.

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 d7f97920703f0f77a6b8b4ec81b37f903a11bcc9..700788c226116ac0bf405f0d46a49ef03ad379b8 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -901,6 +901,9 @@ const char kSpeculativeResourcePrefetchingDisabled[] = "disabled";
 // Speculative resource prefetching is enabled.
 const char kSpeculativeResourcePrefetchingEnabled[] = "enabled";
 
+// Speculative resource prefetching is enabled for external requests.
+const char kSpeculativeResourceExternalPrefetchingEnabled[] = "external";
+
 // Speculative resource prefetching will only learn about resources that need to
 // be prefetched but will not prefetch them.
 const char kSpeculativeResourcePrefetchingLearning[] = "learning";