Revert of [tools] Support custom script injection for callstats.py (patchset...

Revert of [tools] Support custom script injection for callstats.py (patchset #1 id:1 of https://codereview.chromium.org/2455623002/ )

Reason for revert:
speculative revert to address regressions on cnn.com benchmark.

Original issue's description:
> [tools] Support custom script injection for callstats.py
>
> This is a poor-man's solution to trigger page interactions.
>
> BUG=

TBR=jochen@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=

Review-Url: https://codereview.chromium.org/2464053005
Cr-Commit-Position: refs/heads/master@{#40710}

tools/callstats.py

@@ -84,8 +84,6 @@ def stop_replay_server(server):
 def generate_injection(f, sites, refreshes=0):
   print >> f, """\
 (function() {
-  var sites =
-    """, json.dumps(sites), """;
   var s = window.sessionStorage.getItem("refreshCounter");
   var refreshTotal = """, refreshes, """;
   var refreshCounter = s ? parseInt(s) : refreshTotal;
@@ -101,15 +99,7 @@ def generate_injection(f, sites, refreshes=0):
       url_wanted = "https://" + url_wanted.substr(7);
     }
     return url.startsWith(url_wanted);
-  }
-  function runCustomScript(site) {
-    if (site.script === undefined) return;
-    /* Combine a script from the given array. */
-    if (typeof site.script !== "string") {
-      site.script = site.script.join(' ');
-    }
-    eval(site.script);
-  }
+  };
   function onLoad(url) {
     for (var item of sites) {
       if (!match(url, item)) continue;
@@ -127,15 +117,13 @@ def generate_injection(f, sites, refreshes=0):
           window.location.reload();
         }
       }, timeout);
-      runCustomScript(item);
       return;
     }
     console.log("Ignoring: " + url);
   };
-  /* Avoid re-triggering the runtime stats for html imports */
-  if (document.currentScript.ownerDocument === document) {
-    onLoad(window.location.href);
-  }
+  var sites =
+    """, json.dumps(sites), """;
+  onLoad(window.location.href);
 })();"""
 
 def get_chrome_flags(js_flags, user_data_dir):