[Autofill Assistant] Support delayed actions.

With this change, the script executor follows
AssistantActionProto.action_delay_ms, when it is set.

Bug: 806868
Change-Id: I4cb7ba2074f316cb27bffb61f9f14dc200639792
Reviewed-on: https://chromium-review.googlesource.com/1186737
Commit-Queue: Ganggui Tang <gogerald@chromium.org>
Reviewed-by: Ganggui Tang <gogerald@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585922}

components/autofill_assistant/browser/assistant_script_executor.cc

@@ -9,6 +9,8 @@
 
 #include "base/bind.h"
 #include "base/callback.h"
+#include "base/single_thread_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "components/autofill_assistant/browser/assistant_protocol_utils.h"
 #include "components/autofill_assistant/browser/assistant_service.h"
 #include "components/autofill_assistant/browser/assistant_ui_controller.h"
@@ -117,6 +119,20 @@ void AssistantScriptExecutor::ProcessNextAction() {
 
   std::unique_ptr<AssistantAction> action = std::move(actions_.front());
   actions_.pop_front();
+  int delay_ms = action->proto().action_delay_ms();
+  if (delay_ms > 0) {
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+        FROM_HERE,
+        base::BindOnce(&AssistantScriptExecutor::ProcessAction,
+                       weak_ptr_factory_.GetWeakPtr(), std::move(action)),
+        base::TimeDelta::FromMilliseconds(delay_ms));
+  } else {
+    ProcessAction(std::move(action));
+  }
+}
+
+void AssistantScriptExecutor::ProcessAction(
+    std::unique_ptr<AssistantAction> action) {
   AssistantAction* action_ptr = action.get();
   action_ptr->ProcessAction(
       this, base::BindOnce(&AssistantScriptExecutor::OnProcessedAction,

components/autofill_assistant/browser/assistant_script_executor.h

@@ -52,6 +52,7 @@ class AssistantScriptExecutor : public AssistantActionDelegate {
  private:
   void OnGetAssistantActions(bool result, const std::string& response);
   void ProcessNextAction();
+  void ProcessAction(std::unique_ptr<AssistantAction> action);
   void GetNextAssistantActions();
   void OnProcessedAction(std::unique_ptr<AssistantAction> action, bool status);
 

components/autofill_assistant/browser/assistant_script_executor_unittest.cc

@@ -5,6 +5,7 @@
 #include "components/autofill_assistant/browser/assistant_script_executor.h"
 
 #include "base/test/mock_callback.h"
+#include "base/test/scoped_task_environment.h"
 #include "components/autofill_assistant/browser/assistant_service.h"
 #include "components/autofill_assistant/browser/client_memory.h"
 #include "components/autofill_assistant/browser/mock_assistant_service.h"
@@ -40,7 +41,9 @@ class AssistantScriptExecutorTest : public testing::Test,
   }
 
  protected:
-  AssistantScriptExecutorTest() {}
+  AssistantScriptExecutorTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::MOCK_TIME) {}
 
   AssistantService* GetAssistantService() override {
     return &mock_assistant_service_;
@@ -62,6 +65,9 @@ class AssistantScriptExecutorTest : public testing::Test,
     return output;
   }
 
+  // scoped_task_environment_ must be first to guarantee other field
+  // creation run in that environment.
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   AssistantScript script_;
   ClientMemory memory_;
   StrictMock<MockAssistantService> mock_assistant_service_;
@@ -169,5 +175,32 @@ TEST_F(AssistantScriptExecutorTest, InterruptActionListOnError) {
             processed_actions2_capture[0].action().tell().message());
 }
 
+TEST_F(AssistantScriptExecutorTest, RunDelayedAction) {
+  ActionsResponseProto actions_response;
+  actions_response.set_server_payload("payload");
+  ActionProto* action = actions_response.add_actions();
+  action->mutable_tell()->set_message("delayed");
+  action->set_action_delay_ms(1000);
+
+  EXPECT_CALL(mock_assistant_service_, OnGetAssistantActions(_, _))
+      .WillOnce(RunOnceCallback<1>(true, Serialize(actions_response)));
+
+  std::vector<ProcessedActionProto> processed_actions_capture;
+  EXPECT_CALL(mock_assistant_service_, OnGetNextAssistantActions(_, _, _))
+      .WillOnce(DoAll(SaveArg<1>(&processed_actions_capture),
+                      RunOnceCallback<2>(true, "")));
+
+  // executor_callback_.Run() not expected to be run just yet, as the action is
+  // delayed.
+  executor_->Run(executor_callback_.Get());
+  EXPECT_TRUE(scoped_task_environment_.MainThreadHasPendingTask());
+
+  // Moving forward in time triggers action execution.
+  EXPECT_CALL(executor_callback_, Run(true));
+  scoped_task_environment_.FastForwardBy(
+      base::TimeDelta::FromMilliseconds(1000));
+  EXPECT_FALSE(scoped_task_environment_.MainThreadHasPendingTask());
+}
+
 }  // namespace
 }  // namespace autofill_assistant

components/autofill_assistant/browser/service.proto

@@ -95,6 +95,9 @@ message ActionsResponseProto {
 
 // An action could be performed.
 message ActionProto {
+  // Wait these many milliseconds before executing the action, if set.
+  optional int32 action_delay_ms = 3;
+
   // Opaque data that should not be interpreted by the client. The client must
   // pass this back unchanged in the next request
   optional bytes server_payload = 4;