[chromedriver] Add Network Presets to Network Throttling feature

chrome/test/chromedriver/chrome/network_conditions.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/json/json_reader.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "base/values.h"
+#include "chrome/test/chromedriver/chrome/network_conditions.h"

[samuong, 2015/03/13 22:30:51]

nit: the #include ".../network_conditions.h" should come first and have a blank
line afterwards

[srawlins, 2015/03/16 18:26:28]

Done.

+#include "chrome/test/chromedriver/chrome/network_list.h"
+#include "chrome/test/chromedriver/chrome/status.h"
+
+NetworkConditions::NetworkConditions() {}
+NetworkConditions::NetworkConditions(
+    bool offline, double latency, double download_throughput,
+    double upload_throughput)
+  : offline(offline),
+    latency(latency),
+    download_throughput(download_throughput),
+    upload_throughput(upload_throughput) {}
+NetworkConditions::~NetworkConditions() {}
+
+Status FindPresetNetwork(std::string network_name,
+                         scoped_ptr<NetworkConditions>* network_conditions) {
+  base::JSONReader json_reader(base::JSON_ALLOW_TRAILING_COMMAS);
+  scoped_ptr<base::Value> networks_value;
+  networks_value.reset(json_reader.ReadToValue(kNetworks));
+  if (!networks_value.get())
+    return Status(kUnknownError,
+                  "could not parse network list because " +
+                  json_reader.GetErrorMessage());
+
+  base::ListValue* networks;
+  if (!networks_value->GetAsList(&networks))
+    return Status(kUnknownError, "malformed networks list");
+
+  for (base::ListValue::iterator it = networks->begin();
+       it != networks->end();
+       ++it) {
+    base::DictionaryValue* network = NULL;
+    if (!(*it)->GetAsDictionary(&network)) {
+      return Status(kUnknownError,
+                    "malformed network in list: should be a dictionary");
+    }
+
+    if (network == NULL)
+      continue;
+
+    std::string title;
+    if (!network->GetString("title", &title)) {
+      return Status(kUnknownError,
+                    "malformed network title: should be a string");
+    }
+    if (title != network_name)
+      continue;

[samuong, 2015/03/13 22:30:51]

is there any reason not to use base::ListValue::Find() rather than iterating
over |networks|?

[srawlins, 2015/03/16 18:26:28]

I don't know how I would use ListValue::Find() here. I'm iterating and querying
each Value on it's "title" property.

[samuong, 2015/03/16 18:43:10]

Oh right, yeah too bad this isn't a dictionary. OK let's just iterate through it
then.

+
+    NetworkConditions tmp_network;
+    if (!network->GetDouble("latency",  &tmp_network.latency)) {
+      return Status(kUnknownError,
+                    "malformed network latency: should be a double");
+    }
+    // Preset list maintains a single "throughput" attribute for each network,
+    // so we use that value for both |download_throughput| and
+    // |upload_throughput| in the NetworkConditions (as does Chrome).
+    if (!network->GetDouble("throughput",  &tmp_network.download_throughput) ||
+        !network->GetDouble("throughput",  &tmp_network.upload_throughput)) {
+      return Status(kUnknownError,
+                    "malformed network throughput: should be a double");
+    }
+
+    // The throughputs of the network presets are listed in kbps, but must be
+    // supplied to the OverrideNetworkConditions command as bps.
+    tmp_network.download_throughput *= 1024;
+    tmp_network.upload_throughput *= 1024;
+
+    // |offline| is always false for now.

[samuong, 2015/03/13 22:30:51]

is |offline| also false when network_name == "offline"?

also, as a workaround for crbug.com/456324, would it work if we set
throughput=0?

[srawlins, 2015/03/16 18:26:28]

No, I tried this before :( Still no communication from Chromedriver to Chrome.

+    tmp_network.offline = false;
+    network_conditions->reset(new NetworkConditions(tmp_network));
+    return Status(kOk);
+  }
+
+  return Status(kUnknownError, "must be a valid network");
+}