Revert "Clear inapplicable disable reasons for component extensions"

This reverts commit 07619eb1.

Reason for revert: Speculative revert for "Linux Chromium OS ASan LSan Tests (1)" failures in unit_tests related to extensions.

Original change's description:
> Clear inapplicable disable reasons for component extensions
> 
> This change ensures that all component extensions are allowed to be activated  despite having some inapplicable disable reasons set.
> 
> In particular, this fixes any specific observed on-device instances where ChromeVox or tts had a disable reason of blocked by policy which prevented it from being activated.
> 
> Bug: 946839,947305
> Test: manually. With a device enterprise enrolled, push down kiosk apps to the device from an admin console. Ensure that ChromeVox still works on all screens.
> Change-Id: I2cedafeb16d4420702188f1516825ce1bad52802
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1553017
> Commit-Queue: David Tseng <dtseng@chromium.org>
> Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#648464}

TBR=dtseng@chromium.org,rdevlin.cronin@chromium.org,devlin@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 946839, 947305
Change-Id: Icf19fe7e45c41ed559a732703844c0874c6cfdd4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1557734Reviewed-by: Samuel Huang <huangs@chromium.org>
Commit-Queue: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#648573}

chrome/browser/extensions/extension_service.cc

@@ -1208,8 +1208,6 @@ void ExtensionService::AddExtension(const Extension* extension) {
 }
 
 void ExtensionService::AddComponentExtension(const Extension* extension) {
-  extension_prefs_->ClearInapplicableDisableReasonsForComponentExtension(
-      extension->id());
   const std::string old_version_string(
       extension_prefs_->GetVersionString(extension->id()));
   const base::Version old_version(old_version_string);

extensions/browser/disable_reason.h

@@ -17,9 +17,6 @@ namespace disable_reason {
 // Also carefully consider if your reason should sync to other devices, and if
 // so, add it to kKnownSyncableDisableReasons in
 // chrome/browser/extensions/extension_sync_service.cc.
-// Finally, consider whether your disable reason applies to component
-// extensions. Reference/update the existing list of applicable reasons in
-// ExtensionsPrefs::ClearInapplicableDisableReasonsForComponentExtension.
 enum DisableReason {
   DISABLE_NONE = 0,
   DISABLE_USER_ACTION = 1 << 0,

extensions/browser/extension_prefs.cc

@@ -783,22 +783,6 @@ void ExtensionPrefs::ClearDisableReasons(const std::string& extension_id) {
                        DISABLE_REASON_CLEAR);
 }
 
-void ExtensionPrefs::ClearInapplicableDisableReasonsForComponentExtension(
-    const std::string& component_extension_id) {
-  static constexpr int kAllowDisableReasons =
-      disable_reason::DISABLE_RELOAD |
-      disable_reason::DISABLE_UNSUPPORTED_REQUIREMENT |
-      disable_reason::DISABLE_CORRUPTED;
-
-  // Some disable reasons incorrectly cause component extensions to never
-  // activate on load. See https://crbug.com/946839 for more details on why we
-  // do this.
-  ModifyDisableReasons(
-      component_extension_id,
-      kAllowDisableReasons & GetDisableReasons(component_extension_id),
-      DISABLE_REASON_REPLACE);
-}
-
 void ExtensionPrefs::ModifyDisableReasons(const std::string& extension_id,
                                           int reasons,
                                           DisableReasonChange change) {

extensions/browser/extension_prefs.h

@@ -281,10 +281,6 @@ class ExtensionPrefs : public KeyedService {
                              int disable_reasons);
   void ClearDisableReasons(const std::string& extension_id);
 
-  // Clears disable reasons that do not apply to component extensions.
-  void ClearInapplicableDisableReasonsForComponentExtension(
-      const std::string& component_extension_id);
-
   // Gets the set of extensions that have been blacklisted in prefs. This will
   // return only the blocked extensions, not the "greylist" extensions.
   // TODO(oleg): Make method names consistent here, in extension service and in

extensions/browser/extension_registrar.cc

@@ -111,7 +111,6 @@ void ExtensionRegistrar::AddExtension(
 void ExtensionRegistrar::AddNewExtension(
     scoped_refptr<const Extension> extension) {
   if (extension_prefs_->IsExtensionBlacklisted(extension->id())) {
-    DCHECK(!Manifest::IsComponentLocation(extension->location()));
     // Only prefs is checked for the blacklist. We rely on callers to check the
     // blacklist before calling into here, e.g. CrxInstaller checks before
     // installation then threads through the install and pending install flow
@@ -119,7 +118,6 @@ void ExtensionRegistrar::AddNewExtension(
     // extensions.
     registry_->AddBlacklisted(extension);
   } else if (delegate_->ShouldBlockExtension(extension.get())) {
-    DCHECK(!Manifest::IsComponentLocation(extension->location()));
     registry_->AddBlocked(extension);
   } else if (extension_prefs_->IsExtensionDisabled(extension->id())) {
     registry_->AddDisabled(extension);