Add fxcrt::AutoRestorer<T>::AbandonRestoration().chromium/3475

Kinda like reaching a commit point, makes going forward more useful.

Change-Id: I7695b6e627d4cd8ed2bccb667d0cabd7f42c7b1c
Reviewed-on: https://pdfium-review.googlesource.com/35970
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/core/fxcrt/autorestorer.h b/core/fxcrt/autorestorer.h
index 745a56fff2..cafa075137 100644
--- a/core/fxcrt/autorestorer.h
+++ b/core/fxcrt/autorestorer.h
@@ -12,10 +12,14 @@ class AutoRestorer {
  public:
   explicit AutoRestorer(T* location)
       : m_Location(location), m_OldValue(*location) {}
-  ~AutoRestorer() { *m_Location = m_OldValue; }
+  ~AutoRestorer() {
+    if (m_Location)
+      *m_Location = m_OldValue;
+  }
+  void AbandonRestoration() { m_Location = nullptr; }
 
  private:
-  T* const m_Location;
+  T* m_Location;
   const T m_OldValue;
 };