Make SimpleCache the default backend on ChromeOS/Linux.

chrome/browser/profiles/profile_impl_io_data.cc

Index: chrome/browser/profiles/profile_impl_io_data.cc
diff --git a/chrome/browser/profiles/profile_impl_io_data.cc b/chrome/browser/profiles/profile_impl_io_data.cc
index 49b9a266cc34c2c570e158fc385a849d6c0683b0..df0e65d32a94352c46b2be9bfffc09d1cd6e0bdb 100644
--- a/chrome/browser/profiles/profile_impl_io_data.cc
+++ b/chrome/browser/profiles/profile_impl_io_data.cc
@@ -88,12 +88,21 @@ net::BackendType ChooseCacheBackendType() {
   }
   const std::string experiment_name =
       base::FieldTrialList::FindFullName("SimpleCacheTrial");
-  if (experiment_name == "ExperimentYes" ||
-      experiment_name == "ExperimentYes2") {
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
+  // TODO(gavinp): Remove this kill-switch experiment in the m53 timeframe.
+  if (base::StartsWith(experiment_name, "Disable",
+                       base::CompareCase::INSENSITIVE_ASCII)) {
+    return net::CACHE_BACKEND_BLOCKFILE;
+  }
+  return net::CACHE_BACKEND_SIMPLE;
+#else
+  if (base::StartsWith(experiment_name, "ExperimentYes",
+                       base::CompareCase::INSENSITIVE_ASCII)) {
     return net::CACHE_BACKEND_SIMPLE;
   }
   return net::CACHE_BACKEND_BLOCKFILE;
-#endif
+#endif  // #if defined(OS_LINUX) || defined(OS_CHROMEOS)

[mmenke, 2016/05/13 19:45:29]

Can this just be:

if (..."Disable"...)
  return net::CACHE_BACKEND_BLOCKFILE;
if (..."ExperimentYes"...)
  return net::CACHE_BACKEND_SIMPLE;

#ifdefs go here

Making disable and enable experiment names per-platform doesn't seem to get us
anything.

+#endif  // #if defined(OS_ANDROID)
 }
 
 }  // namespace