[Extensions] Migrate ExtensionInstallPrompt::Delegate to be a callback

The ExtensionInstallPrompt + Delegate setup is prone to lifetime issues because
the caller of the delegate is a UI element, whereas the delegate is usually
somehow part of the extension system. At best, this makes lifetime management a
little confusing, but at worst, it's fundamentally flawed because UI ownership
and extension system ownership are very complicated at times like shutdown.

Instead, migrate the delegate to be a callback, where lifetime management is
more explicit (and safe if the fka delegate is deleted). Also update a few
confusing parts of the Cocoa install prompt API.

BUG=567844
TBR=benwells@chromium.org (small c/b/ui/extensions changes)

Review URL: https://codereview.chromium.org/1534123002

Cr-Commit-Position: refs/heads/master@{#368238}

3 files changed, 22 insertions, 18 deletions

diff --git a/extensions/browser/api/management/management_api.cc b/extensions/browser/api/management/management_api.cc
index 81fe012..2511aee 100644
--- a/extensions/browser/api/management/management_api.cc
+++ b/extensions/browser/api/management/management_api.cc
@@ -451,8 +451,10 @@ ExtensionFunction::ResponseAction ManagementSetEnabledFunction::Run() {
       if (!user_gesture())
         return RespondNow(Error(keys::kGestureNeededForEscalationError));
 
-      AddRef();  // Matched in InstallUIProceed/InstallUIAbort
-      install_prompt_ = delegate->SetEnabledFunctionDelegate(this, extension);
+      AddRef();  // Matched in OnInstallPromptDone().
+      install_prompt_ = delegate->SetEnabledFunctionDelegate(
+          GetSenderWebContents(), browser_context(), extension,
+          base::Bind(&ManagementSetEnabledFunction::OnInstallPromptDone, this));
       return RespondLater();
     }
     if (prefs->GetDisableReasons(extension_id_) &
@@ -474,18 +476,18 @@ ExtensionFunction::ResponseAction ManagementSetEnabledFunction::Run() {
   return RespondNow(NoArguments());
 }
 
-void ManagementSetEnabledFunction::InstallUIProceed() {
-  ManagementAPI::GetFactoryInstance()
-      ->Get(browser_context())
-      ->GetDelegate()
-      ->EnableExtension(browser_context(), extension_id_);
-  Respond(OneArgument(new base::FundamentalValue(true)));
-  Release();
-}
+void ManagementSetEnabledFunction::OnInstallPromptDone(bool did_accept) {
+  if (did_accept) {
+    ManagementAPI::GetFactoryInstance()
+        ->Get(browser_context())
+        ->GetDelegate()
+        ->EnableExtension(browser_context(), extension_id_);
+    Respond(OneArgument(new base::FundamentalValue(true)));
+  } else {
+    Respond(Error(keys::kUserDidNotReEnableError));
+  }
 
-void ManagementSetEnabledFunction::InstallUIAbort(bool user_initiated) {
-  Respond(Error(keys::kUserDidNotReEnableError));
-  Release();
+  Release();  // Balanced in Run().
 }
 
 void ManagementSetEnabledFunction::OnRequirementsChecked(
diff --git a/extensions/browser/api/management/management_api.h b/extensions/browser/api/management/management_api.h
index f37e9c9..fc9b563 100644
--- a/extensions/browser/api/management/management_api.h
+++ b/extensions/browser/api/management/management_api.h
@@ -114,9 +114,6 @@ class ManagementSetEnabledFunction : public UIThreadExtensionFunction {
 
   ManagementSetEnabledFunction();
 
-  void InstallUIProceed();
-  void InstallUIAbort(bool user_initiated);
-
  protected:
   ~ManagementSetEnabledFunction() override;
 
@@ -124,6 +121,8 @@ class ManagementSetEnabledFunction : public UIThreadExtensionFunction {
   ResponseAction Run() override;
 
  private:
+  void OnInstallPromptDone(bool did_accept);
+
   void OnRequirementsChecked(const std::vector<std::string>& requirements);
 
   std::string extension_id_;
diff --git a/extensions/browser/api/management/management_api_delegate.h b/extensions/browser/api/management/management_api_delegate.h
index f7b15a7..9e127ee 100644
--- a/extensions/browser/api/management/management_api_delegate.h
+++ b/extensions/browser/api/management/management_api_delegate.h
@@ -14,6 +14,7 @@
 
 namespace content {
 class BrowserContext;
+class WebContents;
 }  // namespace content
 
 namespace extensions {
@@ -78,8 +79,10 @@ class ManagementAPIDelegate {
   // Used to show a dialog prompt in chrome when management.setEnabled extension
   // function is called.
   virtual scoped_ptr<InstallPromptDelegate> SetEnabledFunctionDelegate(
-      ManagementSetEnabledFunction* function,
-      const Extension* extension) const = 0;
+      content::WebContents* web_contents,
+      content::BrowserContext* browser_context,
+      const Extension* extension,
+      const base::Callback<void(bool)>& callback) const = 0;
 
   // Returns a new RequirementsChecker.
   virtual scoped_ptr<RequirementsChecker> CreateRequirementsChecker() const = 0;