Update ChromeDriver to accept W3C format InitSession

chrome/test/chromedriver/session_commands.cc

Index: chrome/test/chromedriver/session_commands.cc
diff --git a/chrome/test/chromedriver/session_commands.cc b/chrome/test/chromedriver/session_commands.cc
index 1a39f53bc3a0574e07e8fb9e9ea019677c0ae3ee..4cfebf9a8d8aab610e5f2a35c2024bc03a1b54fb 100644
--- a/chrome/test/chromedriver/session_commands.cc
+++ b/chrome/test/chromedriver/session_commands.cc
@@ -177,13 +177,20 @@ Status InitSessionHelper(const InitSessionParams& bound_params,
       new WebDriverLog(WebDriverLog::kDriverType, Log::kAll));
   const base::DictionaryValue* desired_caps;
   bool w3c_capability = false;
-  if (params.GetDictionary("capabilities.desiredCapabilities", &desired_caps)
+  if (params.GetDictionary("capabilities.alwaysMatch", &desired_caps)
       && desired_caps->GetBoolean("chromeOptions.w3c", &w3c_capability)
       && w3c_capability)
+    // TODO(johnchen): Handle capabilities.firstMatch.

[samuong, 2017/03/29 17:07:48]

When you go and implement this TODO, you'll need to modify |desired_caps|, which
is currently const. But you can change this in a future CL.

     session->w3c_compliant = true;
-  else if (!params.GetDictionary("desiredCapabilities", &desired_caps) &&
-     !params.GetDictionary("capabilities.desiredCapabilities", &desired_caps))
-    return Status(kUnknownError, "cannot find dict 'desiredCapabilities'");
+  else if (params.GetDictionary("capabilities.desiredCapabilities",
+                                &desired_caps)
+           && desired_caps->GetBoolean("chromeOptions.w3c", &w3c_capability)
+           && w3c_capability)
+    // TODO(johnchen): Remove when clients stop using this.
+    session->w3c_compliant = true;

[samuong, 2017/03/29 17:07:48]

nit: style guide says to use {}s when there are more than two lines, so use them
everywhere in this if-else-if-else-if block

+  else if (!params.GetDictionary("desiredCapabilities", &desired_caps))
+    return Status(kUnknownError,

[samuong, 2017/03/29 17:07:48]

can you change this to kSessionNotCreatedException?

+                  "cannot find dict 'alwaysMatch' or 'desiredCapabilities'");

[samuong, 2017/03/29 17:07:48]

nit: update error message

 
   Capabilities capabilities;
   Status status = capabilities.Parse(*desired_caps);