Init Clipboard DLP controller only if not existing

Avoided the recreating of EnterpriseClipboardDlpController
every time on policy update by creating a new instance
only if there's not any instance running.

Bug: 1135480
Change-Id: I65b17ab262ceb1572b104dbc2a4456c1c4b55663
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2450280Reviewed-by: Sergey Poromov <poromov@chromium.org>
Reviewed-by: Darwin Huang <huangdarwin@chromium.org>
Reviewed-by: Nikita Podguzov <nikitapodguzov@chromium.org>
Commit-Queue: Aya Elsayed <ayaelattar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814574}

chrome/browser/chromeos/policy/dlp/enterprise_clipboard_dlp_controller.cc

@@ -34,7 +34,8 @@ constexpr int kToastDurationMs = 2500;
 
 // static
 void EnterpriseClipboardDlpController::Init() {
-  new EnterpriseClipboardDlpController();
+  if (!HasInstance())
+    new EnterpriseClipboardDlpController();
 }
 
 bool EnterpriseClipboardDlpController::IsDataReadAllowed(

ui/base/clipboard/clipboard_dlp_controller.cc

@@ -11,6 +11,11 @@ ClipboardDlpController* ClipboardDlpController::Get() {
   return g_clipboard_dlp_controller_;
 }
 
+// static
+bool ClipboardDlpController::HasInstance() {
+  return g_clipboard_dlp_controller_ != nullptr;
+}
+
 // static
 void ClipboardDlpController::DeleteInstance() {
   if (!g_clipboard_dlp_controller_)

ui/base/clipboard/clipboard_dlp_controller.h

@@ -19,6 +19,9 @@ class COMPONENT_EXPORT(UI_BASE_CLIPBOARD) ClipboardDlpController {
   // Returns a pointer to the existing instance of the class.
   static ClipboardDlpController* Get();
 
+  // Returns true if an instance exists, without forcing an initialization.
+  static bool HasInstance();
+
   // Deletes the existing instance of the class if it's already created.
   // Indicates that restricting clipboard content is no longer required.
   static void DeleteInstance();