Move ChromeRequirementsChecker to //extensions as a PreloadCheck

chrome/browser/extensions/extension_install_checker.h

Index: chrome/browser/extensions/extension_install_checker.h
diff --git a/chrome/browser/extensions/extension_install_checker.h b/chrome/browser/extensions/extension_install_checker.h
index 17da24274b9bba8494c573e02a5ef64306f8cd5b..f548474ba8d70100917cdfc007b1b54523d328e7 100644
--- a/chrome/browser/extensions/extension_install_checker.h
+++ b/chrome/browser/extensions/extension_install_checker.h
@@ -20,8 +20,6 @@ class Profile;
 
 namespace extensions {
 
-class RequirementsChecker;
-
 // Performs common checks for validating whether an extension may be installed.
 // This class should be Start()-ed at most once.
 class ExtensionInstallChecker {
@@ -60,10 +58,9 @@ class ExtensionInstallChecker {
   // Returns true if any checks are currently running.
   bool is_running() const { return running_checks_ != 0; }
 
-  // Returns the requirement violations. A non-empty list is considered to be
-  // a check failure.
-  const std::vector<std::string>& requirement_errors() const {
-    return requirement_errors_;
+  // Returns the error message for requirement violations, if any were found.
+  const std::string& requirements_error_message() const {
+    return requirements_error_message_;
   }
 
   // Returns the blacklist error of the extension. Note that there is only an
@@ -79,13 +76,17 @@ class ExtensionInstallChecker {
   void SetPolicyCheckForTesting(std::unique_ptr<PreloadCheck> policy_check) {
     policy_check_ = std::move(policy_check);
   }
+  void SetRequirementsCheckForTesting(
+      std::unique_ptr<PreloadCheck> requirements_check) {
+    requirements_check_ = std::move(requirements_check);
+  }
 
  protected:
   virtual void CheckManagementPolicy();
   void OnManagementPolicyCheckDone(PreloadCheck::Errors errors);
 
   virtual void CheckRequirements();
-  void OnRequirementsCheckDone(const std::vector<std::string>& errors);
+  void OnRequirementsCheckDone(PreloadCheck::Errors errors);
 
   virtual void CheckBlacklistState();
   void OnBlacklistStateCheckDone(PreloadCheck::Errors errors);
@@ -100,8 +101,8 @@ class ExtensionInstallChecker {
   scoped_refptr<const Extension> extension_;
 
   // Checks requirements specified in the manifest.
-  std::unique_ptr<RequirementsChecker> requirements_checker_;
-  std::vector<std::string> requirement_errors_;
+  std::unique_ptr<PreloadCheck> requirements_check_;
+  std::string requirements_error_message_;
 
   // Checks if the extension is blacklisted.
   std::unique_ptr<PreloadCheck> blacklist_check_;