Rename TabLifecycleUnit to TabLifecycleUnitExternal.

With this CL, TabLifecycleUnit is renamed to TabLifecycleUnitExternal
and it no longer inherits from LifecycleUnit. The name
"TabLifecycleUnitExternal" makes it clear that this interface is
exposed outside of chrome/browser/resource_coordinator/, and not
inheriting from LifecycleUnit restricts what's available outside
of chrome/browser/resource_coordinator/.

Also, this CL removes TabLifecycleUnitHolder.
TabLifecycleUnitExternal::FromWebContents will be implemented by
a map lookup in TabLifecycleUnitSource.

Bug: 775644
Change-Id: Ia8fa3b3a8c7f1d4289fc15f3f4d983192dda4db6
Reviewed-on: https://chromium-review.googlesource.com/788271
Commit-Queue: François Doray <fdoray@chromium.org>
Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521352}

chrome/browser/BUILD.gn

@@ -2562,8 +2562,8 @@ split_static_library("browser") {
       "resource_coordinator/lifecycle_unit.h",
       "resource_coordinator/lifecycle_unit_source_observer.h",
       "resource_coordinator/tab_lifecycle_observer.h",
-      "resource_coordinator/tab_lifecycle_unit.cc",
-      "resource_coordinator/tab_lifecycle_unit.h",
+      "resource_coordinator/tab_lifecycle_unit_external.cc",
+      "resource_coordinator/tab_lifecycle_unit_external.h",
       "resource_coordinator/tab_manager.cc",
       "resource_coordinator/tab_manager.h",
       "resource_coordinator/tab_manager_delegate_chromeos.cc",

chrome/browser/resource_coordinator/tab_lifecycle_unit.cc

-// Copyright 2017 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 "chrome/browser/resource_coordinator/tab_lifecycle_unit.h"
-
-#include "base/macros.h"
-#include "content/public/browser/web_contents_user_data.h"
-
-namespace resource_coordinator {
-
-namespace {
-
-class TabLifecycleUnitHolder
-    : public content::WebContentsUserData<TabLifecycleUnitHolder> {
- public:
-  explicit TabLifecycleUnitHolder(content::WebContents*) {}
-  TabLifecycleUnit* tab_lifecycle_unit() const { return tab_lifecycle_unit_; }
-  void set_tab_lifecycle_unit(TabLifecycleUnit* tab_lifecycle_unit) {
-    tab_lifecycle_unit_ = tab_lifecycle_unit;
-  }
-
- private:
-  TabLifecycleUnit* tab_lifecycle_unit_ = nullptr;
-
-  DISALLOW_COPY_AND_ASSIGN(TabLifecycleUnitHolder);
-};
-
-}  // namespace
-
-// static
-TabLifecycleUnit* TabLifecycleUnit::FromWebContents(
-    content::WebContents* web_contents) {
-  TabLifecycleUnitHolder* holder =
-      TabLifecycleUnitHolder::FromWebContents(web_contents);
-  return holder ? holder->tab_lifecycle_unit() : nullptr;
-}
-
-// static
-void TabLifecycleUnit::SetForWebContents(content::WebContents* web_contents,
-                                         TabLifecycleUnit* tab_lifecycle_unit) {
-  TabLifecycleUnitHolder::CreateForWebContents(web_contents);
-  TabLifecycleUnitHolder::FromWebContents(web_contents)
-      ->set_tab_lifecycle_unit(tab_lifecycle_unit);
-}
-
-}  // namespace resource_coordinator
-
-DEFINE_WEB_CONTENTS_USER_DATA_KEY(resource_coordinator::TabLifecycleUnitHolder);

chrome/browser/resource_coordinator/tab_lifecycle_unit_external.cc

+// Copyright 2017 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 "chrome/browser/resource_coordinator/tab_lifecycle_unit_external.h"
+
+namespace resource_coordinator {
+
+// static
+TabLifecycleUnitExternal* TabLifecycleUnitExternal::FromWebContents(
+    content::WebContents* web_contents) {
+  // TODO(fdoray): Implement this. https://crbug.com/775644
+  return nullptr;
+}
+
+}  // namespace resource_coordinator

chrome/browser/resource_coordinator/tab_lifecycle_unit.h → chrome/browser/resource_coordinator/tab_lifecycle_unit_external.h

@@ -2,47 +2,42 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_LIFECYCLE_UNIT_H_
-#define CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_LIFECYCLE_UNIT_H_
-
-#include "chrome/browser/resource_coordinator/lifecycle_unit.h"
+#ifndef CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_LIFECYCLE_UNIT_EXTERNAL_H_
+#define CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_LIFECYCLE_UNIT_EXTERNAL_H_
 
 namespace content {
-class RenderProcessHost;
 class WebContents;
 }  // namespace content
 
 namespace resource_coordinator {
 
-// Represents a tab.
-class TabLifecycleUnit : public LifecycleUnit {
+// Interface to control the lifecycle of a tab exposed outside of
+// chrome/browser/resource_coordinator/.
+class TabLifecycleUnitExternal {
  public:
-  // Returns the TabLifecycleUnit associated with |web_contents|, or nullptr if
-  // the WebContents is not associated with a tab.
-  static TabLifecycleUnit* FromWebContents(content::WebContents* web_contents);
+  // Returns the TabLifecycleUnitExternal associated with |web_contents|, or
+  // nullptr if the WebContents is not associated with a tab.
+  static TabLifecycleUnitExternal* FromWebContents(
+      content::WebContents* web_contents);
+
+  virtual ~TabLifecycleUnitExternal() = default;
 
   // Returns the WebContents associated with this tab.
   virtual content::WebContents* GetWebContents() const = 0;
 
-  // Returns the RenderProcessHost associated with this tab.
-  virtual content::RenderProcessHost* GetRenderProcessHost() const = 0;
-
-  // Returns true if the tab is playing audio, has played audio recently, is
-  // accessing the microphone, is accessing the camera or is being mirrored.
-  virtual bool IsMediaTab() const = 0;
-
   // Returns true if this tab can be automatically discarded.
   virtual bool IsAutoDiscardable() const = 0;
 
   // Allows/disallows this tab to be automatically discarded.
   virtual void SetAutoDiscardable(bool auto_discardable) = 0;
 
- protected:
-  // Sets the TabLifecycleUnit associated with |web_contents|.
-  static void SetForWebContents(content::WebContents* web_contents,
-                                TabLifecycleUnit* tab_lifecycle_unit);
+  // Discards the tab.
+  virtual void DiscardTab() = 0;
+
+  // Returns true if the tab is discarded.
+  virtual bool IsDiscarded() const = 0;
 };
 
 }  // namespace resource_coordinator
 
-#endif  // CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_LIFECYCLE_UNIT_H_
+#endif  // CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_LIFECYCLE_UNIT_EXTERNAL_H_

chrome/browser/resource_coordinator/tab_lifecycle_unit_unittest.cc

-// Copyright 2017 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 "chrome/browser/resource_coordinator/tab_lifecycle_unit.h"
-
-#include "base/macros.h"
-#include "chrome/test/base/chrome_render_view_host_test_harness.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace resource_coordinator {
-
-namespace {
-
-class DummyTabLifecycleUnit : public TabLifecycleUnit {
- public:
-  explicit DummyTabLifecycleUnit(content::WebContents* contents)
-      : contents_(contents) {
-    TabLifecycleUnit::SetForWebContents(contents_, this);
-  }
-
-  ~DummyTabLifecycleUnit() override {
-    TabLifecycleUnit::SetForWebContents(contents_, nullptr);
-  }
-
-  // TabLifecycleUnit:
-  content::WebContents* GetWebContents() const override { return nullptr; }
-  content::RenderProcessHost* GetRenderProcessHost() const override {
-    return nullptr;
-  }
-  bool IsMediaTab() const override { return false; }
-  bool IsAutoDiscardable() const override { return false; }
-  void SetAutoDiscardable(bool) override {}
-
-  // LifecycleUnit:
-  base::string16 GetTitle() const override { return base::string16(); }
-  std::string GetIconURL() const override { return std::string(); }
-  SortKey GetSortKey() const override { return SortKey(); }
-  State GetState() const override { return State::LOADED; }
-  int GetEstimatedMemoryFreedOnDiscardKB() const override { return 0; }
-  bool CanDiscard(DiscardReason) const override { return false; }
-  bool Discard(DiscardReason) override { return false; }
-
- private:
-  content::WebContents* const contents_;
-
-  DISALLOW_COPY_AND_ASSIGN(DummyTabLifecycleUnit);
-};
-
-}  // namespace
-
-using TabLifecycleUnitTest = ChromeRenderViewHostTestHarness;
-
-TEST_F(TabLifecycleUnitTest, FromWebContentsNullByDefault) {
-  EXPECT_FALSE(TabLifecycleUnit::FromWebContents(web_contents()));
-}
-
-TEST_F(TabLifecycleUnitTest, SetForWebContents) {
-  {
-    DummyTabLifecycleUnit tab_lifecycle_unit(web_contents());
-    EXPECT_EQ(&tab_lifecycle_unit,
-              TabLifecycleUnit::FromWebContents(web_contents()));
-  }
-  EXPECT_FALSE(TabLifecycleUnit::FromWebContents(web_contents()));
-  {
-    DummyTabLifecycleUnit tab_lifecycle_unit(web_contents());
-    EXPECT_EQ(&tab_lifecycle_unit,
-              TabLifecycleUnit::FromWebContents(web_contents()));
-  }
-  EXPECT_FALSE(TabLifecycleUnit::FromWebContents(web_contents()));
-}
-
-}  // namespace resource_coordinator

chrome/test/BUILD.gn

@@ -2746,7 +2746,6 @@ test("unit_tests") {
       "../browser/page_load_metrics/observers/session_restore_page_load_metrics_observer_unittest.cc",
       "../browser/resource_coordinator/background_tab_navigation_throttle_unittest.cc",
       "../browser/resource_coordinator/lifecycle_unit_unittest.cc",
-      "../browser/resource_coordinator/tab_lifecycle_unit_unittest.cc",
       "../browser/resource_coordinator/tab_manager_delegate_chromeos_unittest.cc",
       "../browser/resource_coordinator/tab_manager_stats_collector_unittest.cc",
       "../browser/resource_coordinator/tab_manager_unittest.cc",