Reland: Various refactoring in TabStripModel tests.

This patch refactors tab_strip_model_unittest.cc and some associated
files in several ways:
* Removes ChromeRenderViewHostTestHarness as a superclass of
  TabStripModelTest, which includes some heavyweight dependencies that
  are unused. This speeds up the suite by about 20% (~6500 ms runtime
  vs. ~8000ms before this patch).
* Changes TestTabStripModelDelegate::RunUnloadListenerBeforeClosing to
  return false, and deletes subclasses that exist solely to override
  that method (all of them, except TabStripDummyDelegate, which is
  renamed to UnloadListenerTabStripModelDelegate).
* Moved several helper classes to be defined immediately before the
  test that uses them.
* Deletes member variables from MockTabStripModelObserver, which are
  unused.
* Fixes lint errors and cleans up unused includes.

Change-Id: Ibb93ff41a21aab4c0b9b9f075df315381959c35c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1538575Reviewed-by: François Doray <fdoray@chromium.org>
Reviewed-by: Erik Chen <erikchen@chromium.org>
Commit-Queue: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#644437}

chrome/browser/resource_coordinator/tab_lifecycle_unit_source_unittest.cc

@@ -5,6 +5,8 @@
 #include "chrome/browser/resource_coordinator/tab_lifecycle_unit_source.h"
 
 #include <memory>
+#include <utility>
+#include <vector>
 
 #include "base/bind.h"
 #include "base/macros.h"
@@ -41,18 +43,6 @@ namespace {
 
 constexpr base::TimeDelta kShortDelay = base::TimeDelta::FromSeconds(1);
 
-class NoUnloadListenerTabStripModelDelegate : public TestTabStripModelDelegate {
- public:
-  NoUnloadListenerTabStripModelDelegate() = default;
-  bool RunUnloadListenerBeforeClosing(content::WebContents* contents) override {
-    // The default TestTabStripModelDelegate prevents tabs from being closed.
-    return false;
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(NoUnloadListenerTabStripModelDelegate);
-};
-
 class MockLifecycleUnitSourceObserver : public LifecycleUnitSourceObserver {
  public:
   MockLifecycleUnitSourceObserver() = default;
@@ -290,7 +280,7 @@ class TabLifecycleUnitSourceTest
     ExpectCanDiscardFalseTrivialAllReasons(first_lifecycle_unit);
 
     // Create a second tab strip.
-    NoUnloadListenerTabStripModelDelegate other_tab_strip_model_delegate;
+    TestTabStripModelDelegate other_tab_strip_model_delegate;
     TabStripModel other_tab_strip_model(&other_tab_strip_model_delegate,
                                         profile());
     other_tab_strip_model.AddObserver(source_);
@@ -457,7 +447,7 @@ class TabLifecycleUnitSourceTest
     return web_contents;
   }
 
-  NoUnloadListenerTabStripModelDelegate tab_strip_model_delegate_;
+  TestTabStripModelDelegate tab_strip_model_delegate_;
   ScopedSetTickClockForTesting scoped_set_tick_clock_for_testing_;
 
   DISALLOW_COPY_AND_ASSIGN(TabLifecycleUnitSourceTest);

chrome/browser/resource_coordinator/tab_manager_unittest.cc

@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <map>
 #include <memory>
+#include <utility>
 #include <vector>
 
 #include "base/bind.h"
@@ -98,14 +99,6 @@ class NonResumingBackgroundTabNavigationThrottle
   DISALLOW_COPY_AND_ASSIGN(NonResumingBackgroundTabNavigationThrottle);
 };
 
-class TabStripModelSimpleDelegate : public TestTabStripModelDelegate {
- public:
-  TabStripModelSimpleDelegate() = default;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(TabStripModelSimpleDelegate);
-};
-
 enum TestIndicies {
   kAutoDiscardable,
   kPinned,

chrome/browser/ui/tabs/tab_strip_model_stats_recorder_unittest.cc

@@ -4,6 +4,9 @@
 
 #include "chrome/browser/ui/tabs/tab_strip_model_stats_recorder.h"
 
+#include <memory>
+#include <utility>
+
 #include "base/macros.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
@@ -21,21 +24,8 @@ using content::WebContents;
 class TabStripModelStatsRecorderTest : public ChromeRenderViewHostTestHarness {
 };
 
-class NoUnloadListenerTabStripModelDelegate : public TestTabStripModelDelegate {
- public:
-  NoUnloadListenerTabStripModelDelegate() {}
-  ~NoUnloadListenerTabStripModelDelegate() override {}
-
-  bool RunUnloadListenerBeforeClosing(WebContents* contents) override {
-    return false;
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(NoUnloadListenerTabStripModelDelegate);
-};
-
 TEST_F(TabStripModelStatsRecorderTest, BasicTabLifecycle) {
-  NoUnloadListenerTabStripModelDelegate delegate;
+  TestTabStripModelDelegate delegate;
   TabStripModel tabstrip(&delegate, profile());
 
   TabStripModelStatsRecorder recorder;
@@ -98,7 +88,7 @@ TEST_F(TabStripModelStatsRecorderTest, BasicTabLifecycle) {
 }
 
 TEST_F(TabStripModelStatsRecorderTest, ObserveMultipleTabStrips) {
-  NoUnloadListenerTabStripModelDelegate delegate;
+  TestTabStripModelDelegate delegate;
   TabStripModel tabstrip1(&delegate, profile());
   TabStripModel tabstrip2(&delegate, profile());
 
@@ -167,7 +157,7 @@ TEST_F(TabStripModelStatsRecorderTest, ObserveMultipleTabStrips) {
 
 TEST_F(TabStripModelStatsRecorderTest,
        NumberOfOtherTabsActivatedBeforeMadeActive) {
-  NoUnloadListenerTabStripModelDelegate delegate;
+  TestTabStripModelDelegate delegate;
   TabStripModel tabstrip(&delegate, profile());
 
   TabStripModelStatsRecorder recorder;
@@ -200,7 +190,7 @@ TEST_F(TabStripModelStatsRecorderTest,
 
 TEST_F(TabStripModelStatsRecorderTest,
        NumberOfOtherTabsActivatedBeforeMadeActive_CycleTabs) {
-  NoUnloadListenerTabStripModelDelegate delegate;
+  TestTabStripModelDelegate delegate;
   TabStripModel tabstrip(&delegate, profile());
 
   TabStripModelStatsRecorder recorder;

chrome/browser/ui/tabs/test_tab_strip_model_delegate.cc

@@ -4,6 +4,8 @@
 
 #include "chrome/browser/ui/tabs/test_tab_strip_model_delegate.h"
 
+#include <vector>
+
 #include "chrome/browser/extensions/tab_helper.h"
 #include "chrome/browser/ui/tab_contents/core_tab_helper.h"
 
@@ -55,7 +57,7 @@ bool TestTabStripModelDelegate::ShouldRunUnloadListenerBeforeClosing(
 
 bool TestTabStripModelDelegate::RunUnloadListenerBeforeClosing(
     content::WebContents* contents) {
-  return true;
+  return false;
 }
 
 TabStripModelDelegate::RestoreTabType