Reland "[iOS] Add Overrides provider"

The provider is used to install overrides.
Reland of https://crrev.com/c/1584265

Bug: 954570
Change-Id: I424b6d59c702094020fec20495145f76b6c18646
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1587886Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654851}

ios/chrome/app/main_controller.mm

@@ -152,6 +152,7 @@
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #include "ios/public/provider/chrome/browser/distribution/app_distribution_provider.h"
 #include "ios/public/provider/chrome/browser/mailto/mailto_handler_provider.h"
+#import "ios/public/provider/chrome/browser/overrides_provider.h"
 #include "ios/public/provider/chrome/browser/signin/chrome_identity_service.h"
 #import "ios/public/provider/chrome/browser/user_feedback/user_feedback_provider.h"
 #import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
@@ -793,6 +794,8 @@ enum class EnterTabSwitcherSnapshotResult {
         notifyForeground:_mainBrowserState];
   }
 
+  ios::GetChromeBrowserProvider()->GetOverridesProvider()->InstallOverrides();
+
   [self scheduleLowPriorityStartupTasks];
 
   [_browserViewWrangler updateDeviceSharingManager];

ios/chrome/browser/providers/chromium_browser_provider.h

@@ -29,6 +29,7 @@ class ChromiumBrowserProvider : public ios::ChromeBrowserProvider {
   SpecialUserProvider* GetSpecialUserProvider() const override;
   SpotlightProvider* GetSpotlightProvider() const override;
   FullscreenProvider* GetFullscreenProvider() const override;
+  OverridesProvider* GetOverridesProvider() const override;
 
  private:
   std::unique_ptr<AppDistributionProvider> app_distribution_provider_;
@@ -41,6 +42,7 @@ class ChromiumBrowserProvider : public ios::ChromeBrowserProvider {
   std::unique_ptr<SpecialUserProvider> special_user_provider_;
   std::unique_ptr<SpotlightProvider> spotlight_provider_;
   std::unique_ptr<FullscreenProvider> fullscreen_provider_;
+  std::unique_ptr<OverridesProvider> overrides_provider_;
 };
 
 #endif  // IOS_CHROME_BROWSER_PROVIDERS_CHROMIUM_BROWSER_PROVIDER_H_

ios/chrome/browser/providers/chromium_browser_provider.mm

@@ -13,6 +13,7 @@
 #include "ios/chrome/browser/providers/signin/chromium_signin_resources_provider.h"
 #include "ios/chrome/browser/providers/ui/chromium_styled_text_field.h"
 #include "ios/public/provider/chrome/browser/distribution/app_distribution_provider.h"
+#include "ios/public/provider/chrome/browser/overrides_provider.h"
 #include "ios/public/provider/chrome/browser/signin/chrome_identity_service.h"
 #include "ios/public/provider/chrome/browser/signin/signin_error_provider.h"
 #import "ios/public/provider/chrome/browser/ui/fullscreen_provider.h"
@@ -33,7 +34,8 @@ ChromiumBrowserProvider::ChromiumBrowserProvider()
       voice_search_provider_(std::make_unique<ChromiumVoiceSearchProvider>()),
       special_user_provider_(std::make_unique<SpecialUserProvider>()),
       spotlight_provider_(std::make_unique<ChromiumSpotlightProvider>()),
-      fullscreen_provider_(std::make_unique<FullscreenProvider>()) {}
+      fullscreen_provider_(std::make_unique<FullscreenProvider>()),
+      overrides_provider_(std::make_unique<OverridesProvider>()) {}
 
 ChromiumBrowserProvider::~ChromiumBrowserProvider() {}
 
@@ -97,3 +99,7 @@ SpotlightProvider* ChromiumBrowserProvider::GetSpotlightProvider() const {
 FullscreenProvider* ChromiumBrowserProvider::GetFullscreenProvider() const {
   return fullscreen_provider_.get();
 }
+
+OverridesProvider* ChromiumBrowserProvider::GetOverridesProvider() const {
+  return overrides_provider_.get();
+}

ios/public/provider/chrome/browser/BUILD.gn

@@ -13,6 +13,8 @@ source_set("browser") {
     "chrome_browser_provider.mm",
     "geolocation_updater_provider.h",
     "geolocation_updater_provider.mm",
+    "overrides_provider.h",
+    "overrides_provider.mm",
   ]
   deps = [
     "//base",

ios/public/provider/chrome/browser/chrome_browser_provider.h

@@ -22,6 +22,7 @@ class BrowserURLRewriterProvider;
 class FullscreenProvider;
 class MailtoHandlerProvider;
 class OmahaServiceProvider;
+class OverridesProvider;
 class SpecialUserProvider;
 class SpotlightProvider;
 class UserFeedbackProvider;
@@ -163,6 +164,9 @@ class ChromeBrowserProvider {
   // Returns an instance of the BrowserURLRewriter provider.
   virtual BrowserURLRewriterProvider* GetBrowserURLRewriterProvider() const;
 
+  // Returns an instance of the Overrides provider;
+  virtual OverridesProvider* GetOverridesProvider() const;
+
   // Adds and removes observers.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);

ios/public/provider/chrome/browser/chrome_browser_provider.mm

@@ -118,6 +118,10 @@ ChromeBrowserProvider::GetBrowserURLRewriterProvider() const {
   return nullptr;
 }
 
+OverridesProvider* ChromeBrowserProvider::GetOverridesProvider() const {
+  return nullptr;
+}
+
 MailtoHandlerProvider* ChromeBrowserProvider::GetMailtoHandlerProvider() const {
   return mailto_handler_provider_.get();
 }

ios/public/provider/chrome/browser/overrides_provider.h

+// Copyright 2019 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 IOS_PUBLIC_PROVIDER_CHROME_BROWSER_OVERRIDES_PROVIDER_H_
+#define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_OVERRIDES_PROVIDER_H_
+
+// Provider for installing overrides.
+class OverridesProvider {
+ public:
+  OverridesProvider();
+  virtual ~OverridesProvider();
+
+  virtual void InstallOverrides();
+};
+
+#endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_OVERRIDES_PROVIDER_H_

ios/public/provider/chrome/browser/overrides_provider.mm

+// Copyright 2019 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.
+
+#import "ios/public/provider/chrome/browser/overrides_provider.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+OverridesProvider::OverridesProvider() = default;
+
+OverridesProvider::~OverridesProvider() = default;
+
+void OverridesProvider::InstallOverrides() {}