Send events in one tick asynchronously in ExecutePerformActions

ExecutePerformActions function is called from testdriver Action API and
Webdriver API, we expect that all the actions expect the last one in
one tick to be sent asynchronously, so that there is no delay between
those actions. To start actions in the next tick, we should wait for
the response from the actions in the current tick, so by default we
should send the last one in the tick synchronously.

Change-Id: Id457bed235f607bd37dcc0bb44ad635b4875fc58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1790386Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Lan Wei <lanwei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#694819}

chrome/test/chromedriver/window_commands.cc

@@ -1286,6 +1286,22 @@ Status ExecutePerformActions(Session* session,
   }
 
   for (size_t i = 0; i < longest_action_list_size; i++) {
+    // Find the last pointer action, and it has to be sent synchronously by
+    // default.
+    size_t last_action = 0;
+    for (size_t j = 0; j < actions_list.size(); j++) {
+      if (actions_list[j].size() > i) {
+        const base::DictionaryValue* action = actions_list[j][i].get();
+        std::string type;
+        std::string action_type;
+        action->GetString("type", &type);
+        action->GetString("subtype", &action_type);
+        if (type != "none" && action_type != "pause") {
+          last_action = j;
+        }
+      }
+    }
+
     // Implements "compute the tick duration" algorithm from W3C spec
     // (https://w3c.github.io/webdriver/#dfn-computing-the-tick-duration).
     // This is the duration for actions in one tick.
@@ -1334,8 +1350,11 @@ Status ExecutePerformActions(Session* session,
           GetOptionalInt(action, "duration", &duration);
           tick_duration = std::max(tick_duration, duration);
         } else {
-          bool async_dispatch_event = false;
-          GetOptionalBool(action, "asyncDispatch", &async_dispatch_event);
+          bool async_dispatch_event = true;
+          if (j == last_action) {
+            async_dispatch_event = false;
+            GetOptionalBool(action, "asyncDispatch", &async_dispatch_event);
+          }
 
           if (type == "key") {
             std::list<KeyEvent> dispatch_key_events;