Script streaming: Add more Finch experiments for streaming policies.

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index f09be50cc455cfccd7b1edc9764228c44469c2f2..5b5d7e55a5de7826f281462872e4b8e4ee57f778 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -473,9 +473,24 @@ WebPreferences RenderViewHostImpl::ComputeWebkitPrefs(const GURL& url) {
     }
   }
 
+  std::string streaming_experiment_group =
+      base::FieldTrialList::FindFullName("V8ScriptStreaming");
   prefs.v8_script_streaming_enabled =
-      command_line.HasSwitch(switches::kEnableV8ScriptStreaming) ||
-      base::FieldTrialList::FindFullName("V8ScriptStreaming") == "Enabled";
+      command_line.HasSwitch(switches::kEnableV8ScriptStreaming);
+  if (streaming_experiment_group == "Enabled") {
+    prefs.v8_script_streaming_enabled = true;

[Mike West, 2014/10/31 14:42:43]

This means that you're going to override the command line switch; is that really
what you want to be doing?

[marja, 2014/10/31 14:47:48]

Yes. People should get this enabled if 1) they got it enabled via Finch *or* 2)
they pass the switch.

See the previous code which did exactly that. Now it's just more complex since
there are several Finch options which will get this enabled.

+    prefs.v8_script_streaming_mode = V8_SCRIPT_STREAMING_MODE_ALL;
+  }

[jochen (gone - plz use gerrit), 2014/11/03 09:09:29]

else if {

[marja, 2014/11/03 09:13:33]

Done.

+  if (streaming_experiment_group == "OnlyAsyncAndDefer") {
+    prefs.v8_script_streaming_enabled = true;
+    prefs.v8_script_streaming_mode =
+        V8_SCRIPT_STREAMING_MODE_ONLY_ASYNC_AND_DEFER;
+  }
+  if (streaming_experiment_group == "AllPlusBlockParserBlocking") {
+    prefs.v8_script_streaming_enabled = true;
+    prefs.v8_script_streaming_mode =
+        V8_SCRIPT_STREAMING_MODE_ALL_PLUS_BLOCK_PARSER_BLOCKING;
+  }
 
   GetContentClient()->browser()->OverrideWebkitPrefs(this, url, &prefs);
   return prefs;