Adding a field trial to enable speculative resource prefetching learning.

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 49ef645197fac32c71d764c576b4a37ea299e331..946ea77f9c0dfb7892ccd786457828346bde36a1 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -612,10 +612,6 @@ const char kEnableSdch[]                    = "enable-sdch";
 // Enable SPDY/3. This is a temporary testing flag.
 const char kEnableSpdy3[]                   = "enable-spdy3";
 
-// Enable speculative resource prefetching.
-const char kEnableSpeculativeResourcePrefetching[] =
-    "enable-speculative-resource-prefetching";
-
 // Enables the stacked tabstrip.
 const char kEnableStackedTabStrip[]         = "enable-stacked-tab-strip";
 
@@ -1189,6 +1185,17 @@ const char kSimulateUpgrade[]               = "simulate-upgrade";
 // ClientSocketReusePolicy.
 const char kSocketReusePolicy[]             = "socket-reuse-policy";
 
+// Speculative resource prefetching.
+const char kSpeculativeResourcePrefetching[] =
+    "speculative-resource-prefetching";
+
+// Speculative resource prefetching is disabled.
+const char kSpeculativeResourcePrefetchingDisabled[] = "disabled";
+
+// Speculative resource prefetching will only learn about resources that need to
+// be prefetched but will not prefetch them.
+const char kSpeculativeResourcePrefetchingLearning[] = "learning";
+
 // Specifies the maximum SSL/TLS version ("ssl3", "tls1", "tls1.1", or
 // "tls1.2").
 const char kSSLVersionMax[]                 = "ssl-version-max";