[MBI] Create AgentSchedulingGroup class and mojo interface.

The AgentSchedulingGroup class is effectively empty, and is not yet
instantiated by anything.
The mojo interface is currently empty.

Bug: 1111231
Change-Id: I0c22cf38033a43c15594863d565b688319a69668
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2348241
Commit-Queue: Tal Pressman <talp@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799943}

content/browser/renderer_host/agent_scheduling_group_host.h

@@ -5,7 +5,11 @@
 #ifndef CONTENT_BROWSER_RENDERER_HOST_AGENT_SCHEDULING_GROUP_HOST_H_
 #define CONTENT_BROWSER_RENDERER_HOST_AGENT_SCHEDULING_GROUP_HOST_H_
 
+#include <memory>
+
+#include "content/common/agent_scheduling_group.mojom.h"
 #include "content/common/content_export.h"
+#include "mojo/public/cpp/bindings/remote.h"
 
 namespace content {
 
@@ -31,12 +35,22 @@ class CONTENT_EXPORT AgentSchedulingGroupHost {
 
   // Should not be called explicitly. Use Get() instead.
   explicit AgentSchedulingGroupHost(RenderProcessHost& process);
-  virtual ~AgentSchedulingGroupHost();
+  ~AgentSchedulingGroupHost();
 
   RenderProcessHost* GetProcess();
 
  private:
+  // The RenderProcessHost this AgentSchedulingGroup is assigned to.
   RenderProcessHost& process_;
+
+  // Internal implementation of content::mojom::AgentSchedulingGroupHost, used
+  // for responding to calls from the (renderer-side) AgentSchedulingGroup.
+  std::unique_ptr<content::mojom::AgentSchedulingGroupHost> mojo_impl_;
+
+  // Remote stub of content::mojom::AgentSchedulingGroup, used for sending calls
+  // to the (renderer-side) AgentSchedulingGroup.
+  std::unique_ptr<mojo::Remote<content::mojom::AgentSchedulingGroup>>
+      mojo_remote_;
 };
 
 }  // namespace content

content/common/BUILD.gn

@@ -431,6 +431,7 @@ mojom("mojo_bindings") {
   disable_variants = true
 
   sources = [
+    "agent_scheduling_group.mojom",
     "associated_interfaces.mojom",
     "child_process.mojom",
     "document_scoped_interface_bundle.mojom",

content/common/agent_scheduling_group.mojom

+// Copyright 2020 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.
+
+module content.mojom;
+
+// Interface for general communication between AgentSchedulingGroup and
+// AgentSchedulingGroupHost.
+interface AgentSchedulingGroupHost {
+};
+
+// Interface for general communication between AgentSchedulingGroupHost and
+// AgentSchedulingGroup.
+interface AgentSchedulingGroup {
+};

content/renderer/BUILD.gn

@@ -45,6 +45,8 @@ target(link_target_type, "renderer") {
     "accessibility/render_accessibility_impl.h",
     "accessibility/render_accessibility_manager.cc",
     "accessibility/render_accessibility_manager.h",
+    "agent_scheduling_group.cc",
+    "agent_scheduling_group.h",
     "android/synchronous_layer_tree_frame_sink_impl.cc",
     "android/synchronous_layer_tree_frame_sink_impl.h",
     "browser_exposed_renderer_interfaces.cc",

content/renderer/agent_scheduling_group.cc

+// Copyright 2020 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 "content/renderer/agent_scheduling_group.h"
+
+namespace content {
+
+AgentSchedulingGroup::AgentSchedulingGroup() = default;
+AgentSchedulingGroup::~AgentSchedulingGroup() = default;
+
+}  // namespace content

content/renderer/agent_scheduling_group.h

+// Copyright 2020 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.
+
+#ifndef CONTENT_RENDERER_AGENT_SCHEDULING_GROUP_H_
+#define CONTENT_RENDERER_AGENT_SCHEDULING_GROUP_H_
+
+#include <memory>
+
+#include "content/common/agent_scheduling_group.mojom.h"
+#include "content/common/content_export.h"
+#include "mojo/public/cpp/bindings/remote.h"
+
+namespace content {
+
+// Renderer-side representation of AgentSchedulingGroup, used for communication
+// with the (browser-side) AgentSchedulingGroupHost. AgentSchedulingGroup is
+// Blink's unit of scheduling and performance isolation, which is the only way
+// to obtain ordering guarantees between different Mojo (associated) interfaces
+// and legacy IPC messages.
+class CONTENT_EXPORT AgentSchedulingGroup {
+ public:
+  AgentSchedulingGroup();
+  ~AgentSchedulingGroup();
+
+  AgentSchedulingGroup(const AgentSchedulingGroup&) = delete;
+  AgentSchedulingGroup(const AgentSchedulingGroup&&) = delete;
+  AgentSchedulingGroup& operator=(const AgentSchedulingGroup&) = delete;
+  AgentSchedulingGroup& operator=(const AgentSchedulingGroup&&) = delete;
+
+ private:
+  // Internal implementation of content::mojom::AgentSchedulingGroup, used for
+  // responding to calls from the (browser-side) AgentSchedulingGroupHost.
+  std::unique_ptr<content::mojom::AgentSchedulingGroup> mojo_impl_;
+
+  // Remote stub of content::mojom::AgentSchedulingGroupHost, used for sending
+  // calls to the (browser-side) AgentSchedulingGroupHost.
+  std::unique_ptr<mojo::Remote<content::mojom::AgentSchedulingGroupHost>>
+      mojo_remote_;
+};
+
+}  // namespace content
+
+#endif