Update extension install prompt to reflect withheld permissions

chrome/browser/extensions/extension_install_prompt.cc

Index: chrome/browser/extensions/extension_install_prompt.cc
diff --git a/chrome/browser/extensions/extension_install_prompt.cc b/chrome/browser/extensions/extension_install_prompt.cc
index dec1aa54f3b756b3d1ba147b74b8179e6c912cf0..8ab04ea7524da8527ed0fea85a20d6dad8184784 100644
--- a/chrome/browser/extensions/extension_install_prompt.cc
+++ b/chrome/browser/extensions/extension_install_prompt.cc
@@ -16,6 +16,7 @@
 #include "chrome/browser/extensions/bundle_installer.h"
 #include "chrome/browser/extensions/extension_install_ui.h"
 #include "chrome/browser/extensions/extension_util.h"
+#include "chrome/browser/extensions/permissions_updater.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
@@ -543,6 +544,8 @@ void ExtensionInstallPrompt::ConfirmBundleInstall(
     const PermissionSet* permissions) {
   DCHECK(ui_loop_ == base::MessageLoop::current());
   bundle_ = bundle;
+  // |bundle|'s extensions have already had their permissions initialized at
+  // this point, so withheld permissions will not show up in the prompt.
   permissions_ = permissions;
   delegate_ = bundle;
   prompt_ = new Prompt(BUNDLE_INSTALL_PROMPT);
@@ -557,6 +560,10 @@ void ExtensionInstallPrompt::ConfirmStandaloneInstall(
     scoped_refptr<Prompt> prompt) {
   DCHECK(ui_loop_ == base::MessageLoop::current());
   extension_ = extension;
+  // Initialize permissions so that withheld permissions don't end up in the
+  // install prompt.
+  extensions::PermissionsUpdater(install_ui_->profile()).InitializePermissions(
+      extension_);

[not at google - send to devlin, 2014/08/28 03:17:32]

A weirdness here is that even though this is a dummy extension we're still going
to prefs to look for it (see the implementation of InitializePermissions). It
works because that ends up reading NULL for the permissions and we end up using
permissions_data()->active_permissions(), which is correct, but still. Weird.
And what if InitializePermissions one day starts writing stuff to prefs?

We need a "no prefs" version of InitializePermissions :\ which implies a static
InitializePermissions-type method ... which is yuck.

Ping this stuff to me tomorrow. I can't think of a particularly nice way of
doing it right now.

[gpdavis, 2014/08/28 17:41:48]

Ping :)

What if we just add a flag to InitializePermissions?  Something like
is_dummy_extension, and if it's true, we don't access prefs and we can add a
comment that indicates that dummy extensions shouldn't be looked for in prefs? 
InitializePermissions isn't called all that many times, so this shouldn't create
too much of an impact elsewhere.

[not at google - send to devlin, 2014/08/28 18:28:02]

Yes! That's the best solution I came up with as well. Modulo a different syntax.
Let's use flags, like:

class PermissionsUpdater {
  enum InitFlag {
    INIT_FLAG_NONE = 0,
    INIT_FLAG_TRANSIENT = 1<<1,
  };

  void InitializePermissions(extension) {
    InitializePermissions(extension, INIT_FLAG_NONE);
  }

  void InitializePermissions(extension, flag) {
    if (flag & INIT_FLAG_TRANSIENT)
      ...  // don't console preferences about |extension|.
  }
};

   permissions_ = extension->permissions_data()->active_permissions();
   delegate_ = delegate;
   prompt_ = prompt;
@@ -583,6 +590,10 @@ void ExtensionInstallPrompt::ConfirmInstall(
     const ShowDialogCallback& show_dialog_callback) {
   DCHECK(ui_loop_ == base::MessageLoop::current());
   extension_ = extension;
+  // Initialize permissions so that withheld permissions don't end up in the
+  // install prompt.
+  extensions::PermissionsUpdater(install_ui_->profile()).InitializePermissions(
+      extension_);
   permissions_ = extension->permissions_data()->active_permissions();
   delegate_ = delegate;
   prompt_ = new Prompt(INSTALL_PROMPT);