Revert "Make AppMenuModel keep most submenus in a vector."

This reverts commit 849315dd.

Reason for revert: Suspecting this CL for compile failures on windows e.g. https://ci.chromium.org/p/chrome/builders/ci/win64-builder-perf/127136
[7893/15918] CXX obj/chrome/browser/ui/ui/app_menu_model.obj
FAILED: obj/chrome/browser/ui/ui/app_menu_model.obj
c:\b\s\w\ir\cache\goma\client\gomacc.exe ..\..\third_party\llvm-build\Release+Asserts\bin\clang-cl.e...(too long)
../../chrome/browser/ui/toolbar/app_menu_model.cc(166,21): error: no class named 'HelpMenuModel' in 'AppMenuModel'
class AppMenuModel::HelpMenuModel : public ui::SimpleMenuModel {
~~~~~~~~~~~~~~^
../../chrome/browser/ui/toolbar/app_menu_model.cc(819,41): error: unknown type name 'HelpMenuModel'; did you mean 'AppMenuModel'?
sub_menus_.push_back(std::make_unique<HelpMenuModel>(this, browser_));
^~~~~~~~~~~~~
AppMenuModel

Original change's description:
> Make AppMenuModel keep most submenus in a vector.
> 
> They are only needed for ownership, so no need to give them names and concrete
> types. Removes some forward declarations from the header and serendipitously
> happens to remove GOOGLE_CHROME_BUILD from the header as well.
> 
> No intended behavior change.
> 
> Bug: 961769
> Change-Id: Ibaaf3375bd9d367b4cc83b9a8ec3e64193750a69
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1894032
> Commit-Queue: Robert Sesek <rsesek@chromium.org>
> Auto-Submit: Nico Weber <thakis@chromium.org>
> Reviewed-by: Robert Sesek <rsesek@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#711431}

TBR=thakis@chromium.org,rsesek@chromium.org

Change-Id: I40cdc0d770d2d49ed568fb2c7d22fa791088c0a2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 961769
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893861Reviewed-by: Kevin McNee <mcnee@chromium.org>
Commit-Queue: Kevin McNee <mcnee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711450}

chrome/browser/ui/toolbar/app_menu_model.cc

@@ -754,10 +754,10 @@ void AppMenuModel::Build() {
   AddSeparator(ui::NORMAL_SEPARATOR);
 
   if (!browser_->profile()->IsOffTheRecord()) {
-    sub_menus_.push_back(
-        std::make_unique<RecentTabsSubMenuModel>(provider_, browser_));
+    recent_tabs_sub_menu_model_ =
+        std::make_unique<RecentTabsSubMenuModel>(provider_, browser_);
     AddSubMenuWithStringId(IDC_RECENT_TABS_MENU, IDS_HISTORY_MENU,
-                           sub_menus_.back().get());
+                           recent_tabs_sub_menu_model_.get());
   }
   AddItemWithStringId(IDC_SHOW_DOWNLOADS, IDS_SHOW_DOWNLOADS);
   if (!browser_->profile()->IsGuestSession()) {
@@ -804,9 +804,9 @@ void AppMenuModel::Build() {
   }
 #endif
 
-  sub_menus_.push_back(std::make_unique<ToolsMenuModel>(this, browser_));
+  tools_menu_model_ = std::make_unique<ToolsMenuModel>(this, browser_);
   AddSubMenuWithStringId(IDC_MORE_TOOLS_MENU, IDS_MORE_TOOLS_MENU,
-                         sub_menus_.back().get());
+                         tools_menu_model_.get());
   AddSeparator(ui::LOWER_SEPARATOR);
   CreateCutCopyPasteMenu();
   AddSeparator(ui::UPPER_SEPARATOR);
@@ -816,8 +816,8 @@ void AppMenuModel::Build() {
 // 'About' item has been moved to this submenu, it's reinstated here for
 // Chromium builds.
 #if BUILDFLAG(GOOGLE_CHROME_BRANDING)
-  sub_menus_.push_back(std::make_unique<HelpMenuModel>(this, browser_));
-  AddSubMenuWithStringId(IDC_HELP_MENU, IDS_HELP_MENU, sub_menus_.back().get());
+  help_menu_model_ = std::make_unique<HelpMenuModel>(this, browser_);
+  AddSubMenuWithStringId(IDC_HELP_MENU, IDS_HELP_MENU, help_menu_model_.get());
 #else
 #if defined(OS_CHROMEOS)
   if (base::FeatureList::IsEnabled(chromeos::features::kSplitSettings))

chrome/browser/ui/toolbar/app_menu_model.h

@@ -21,6 +21,7 @@
 class AppMenuIconController;
 class BookmarkSubMenuModel;
 class Browser;
+class RecentTabsSubMenuModel;
 
 namespace {
 class MockAppMenuModel;
@@ -179,6 +180,7 @@ class AppMenuModel : public ui::SimpleMenuModel,
   void CreateZoomMenu();
 
  private:
+  class HelpMenuModel;
   friend class ::MockAppMenuModel;
 
   bool ShouldShowNewIncognitoWindowMenuItem();
@@ -211,11 +213,19 @@ class AppMenuModel : public ui::SimpleMenuModel,
   // Label of the zoom label in the zoom menu item.
   base::string16 zoom_label_;
 
+#if defined(GOOGLE_CHROME_BUILD)
+  // Help menu.
+  std::unique_ptr<HelpMenuModel> help_menu_model_;
+#endif
+
+  // Tools menu.
+  std::unique_ptr<ToolsMenuModel> tools_menu_model_;
+
   // Bookmark submenu.
   std::unique_ptr<BookmarkSubMenuModel> bookmark_sub_menu_model_;
 
-  // Other submenus.
-  std::vector<std::unique_ptr<ui::SimpleMenuModel>> sub_menus_;
+  // Recent Tabs submenu.
+  std::unique_ptr<RecentTabsSubMenuModel> recent_tabs_sub_menu_model_;
 
   ui::AcceleratorProvider* provider_;  // weak