Modifies AssistantInteractionController for response processing v2.

In response processing v2, the pending response will be committed at
the earliest opportunity so that it can begin rendering.

This CL should *not* affect response processing v1.

Follow up CLs will make additional changes to processing logic and
rendering logic to accommodate this new streaming model.

Bug: b:129411551
Change-Id: I86c22929eb24945f104a06fbbe5ae0b1468caa5f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2063264
Commit-Queue: David Black <dmblack@google.com>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743211}

ash/assistant/assistant_interaction_controller.h

@@ -147,7 +147,7 @@ class AssistantInteractionController
   void StopActiveInteraction(bool cancel_conversation);
 
   InputModality GetDefaultInputModality() const;
-
+  AssistantResponse* GetResponseForActiveInteraction();
   AssistantVisibility GetVisibility() const;
   bool IsVisible() const;
 

ash/assistant/model/assistant_interaction_model.cc

@@ -107,7 +107,7 @@ void AssistantInteractionModel::SetPendingResponse(
   pending_response_ = std::move(pending_response);
 }
 
-void AssistantInteractionModel::FinalizePendingResponse() {
+void AssistantInteractionModel::CommitPendingResponse() {
   DCHECK(pending_response_);
   response_ = std::move(pending_response_);
   NotifyResponseChanged();

ash/assistant/model/assistant_interaction_model.h

@@ -106,16 +106,19 @@ class COMPONENT_EXPORT(ASSISTANT_MODEL) AssistantInteractionModel {
   // Returns the pending response for the interaction.
   AssistantResponse* pending_response() { return pending_response_.get(); }
 
-  // Finalizes the pending response for the interaction.
-  void FinalizePendingResponse();
+  // Commits the pending response for the interaction. Note that this will cause
+  // the previously committed response, if one exists, to be animated off stage
+  // after which the newly committed response will begin rendering.
+  void CommitPendingResponse();
 
   // Clears the pending response for the interaction.
   void ClearPendingResponse();
 
-  // Returns the finalized response for the interaction.
+  // Returns the committed response for the interaction.
+  AssistantResponse* response() { return response_.get(); }
   const AssistantResponse* response() const { return response_.get(); }
 
-  // Clears the finalized response for the interaction.
+  // Clears the committed response for the interaction.
   void ClearResponse();
 
   // Updates the speech level in dB.

ash/assistant/model/assistant_response.h

@@ -21,6 +21,7 @@ namespace ash {
 class AssistantResponseObserver;
 class AssistantUiElement;
 
+// TODO(dmblack): Remove ProcessingState after launch of response processing v2.
 // Models a renderable Assistant response.
 // It is refcounted so that views that display the response can safely
 // reference the data inside this response.