MacPWAs: Re-create app shims when arch changes

In crbug.com/353047, we encountered the problem where Chrome
would upgrade itself from 32-bit to 64-bit, but app shims
would be stuck on 32-bit. A mechanism was added to upgrade
the shims "when needed", based on a  kAppShortcutsVersion local
preference. This number has been incremented several times for
various incompatibilities.

Add a separate kAppShortcutsArch preference which saves the
architecture that apps have been being created in. Whenever
this does not match base::SysInfo::OperatingSystemArchitecture,
re-create all shims.

This will fix the situation whereby a user data dir, including
all of its local prefs, is copied from an Intel mac to an ARM
mac.

A few caveats:
- This will only re-create PWA shims. Legacy apps will need to
  be re-launched from Chrome.
- This only fixes the issue if the user launches Chrome before
  launching a PWA. The PWA shim copied from x86, if it succeeds
  in running, will start Chrome with the start URL for the PWA.

Bug: 1117599
Change-Id: I4d9e1a87e91c1d461b592b0a8250b22120368d94
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2444130
Commit-Queue: ccameron <ccameron@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813631}

chrome/browser/apps/platform_apps/shortcut_manager.cc

@@ -11,6 +11,7 @@
 #include "base/one_shot_event.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/system/sys_info.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ -36,13 +37,23 @@ using extensions::Extension;
 
 namespace {
 
+#if defined(OS_MAC)
 // This version number is stored in local prefs to check whether app shortcuts
 // need to be recreated. This might happen when we change various aspects of app
 // shortcuts like command-line flags or associated icons, binaries, etc.
-#if defined(OS_MAC)
 const int kCurrentAppShortcutsVersion = APP_SHIM_VERSION_NUMBER;
+
+// The architecture that was last used to create app shortcuts for this user
+// directory.
+std::string CurrentAppShortcutsArch() {
+  return base::SysInfo::OperatingSystemArchitecture();
+}
 #else
+// Non-mac platforms do not update shortcuts.
 const int kCurrentAppShortcutsVersion = 0;
+std::string CurrentAppShortcutsArch() {
+  return "";
+}
 #endif
 
 // Delay in seconds before running UpdateShortcutsForAllApps.
@@ -75,6 +86,7 @@ void AppShortcutManager::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   // Indicates whether app shortcuts have been created.
   registry->RegisterIntegerPref(prefs::kAppShortcutsVersion, 0);
+  registry->RegisterStringPref(prefs::kAppShortcutsArch, "");
 }
 
 AppShortcutManager::AppShortcutManager(Profile* profile)
@@ -169,6 +181,8 @@ void AppShortcutManager::UpdateShortcutsForAllAppsNow() {
 void AppShortcutManager::SetCurrentAppShortcutsVersion() {
   profile_->GetPrefs()->SetInteger(prefs::kAppShortcutsVersion,
                                    kCurrentAppShortcutsVersion);
+  profile_->GetPrefs()->SetString(prefs::kAppShortcutsArch,
+                                  CurrentAppShortcutsArch());
 }
 
 void AppShortcutManager::UpdateShortcutsForAllAppsIfNeeded() {
@@ -179,8 +193,13 @@ void AppShortcutManager::UpdateShortcutsForAllAppsIfNeeded() {
 
   int last_version =
       profile_->GetPrefs()->GetInteger(prefs::kAppShortcutsVersion);
-  if (last_version >= kCurrentAppShortcutsVersion)
+  std::string last_arch =
+      profile_->GetPrefs()->GetString(prefs::kAppShortcutsArch);
+
+  if (last_version == kCurrentAppShortcutsVersion &&
+      last_arch == CurrentAppShortcutsArch()) {
     return;
+  }
 
   content::GetUIThreadTaskRunner({})->PostDelayedTask(
       FROM_HERE,

chrome/common/pref_names.cc

@@ -2602,6 +2602,12 @@ const char kAppListLocalState[] = "app_list.local_state";
 // Increasing this causes all app shortcuts to be recreated.
 const char kAppShortcutsVersion[] = "apps.shortcuts_version";
 
+// A string indicating the architecture in which app shortcuts have been
+// created. If this changes (e.g, due to migrating one's home directory
+// from an Intel mac to an ARM mac), then this will cause all shortcuts to be
+// re-created.
+const char kAppShortcutsArch[] = "apps.shortcuts_arch";
+
 // A string pref for storing the salt used to compute the pepper device ID.
 const char kDRMSalt[] = "settings.privacy.drm_salt";
 // A boolean pref that enables the (private) pepper GetDeviceID() call and

chrome/common/pref_names.h

@@ -873,6 +873,7 @@ extern const char kAppListLocalState[];
 #endif
 
 extern const char kAppShortcutsVersion[];
+extern const char kAppShortcutsArch[];
 
 extern const char kDRMSalt[];
 extern const char kEnableDRM[];