Implementing recent pages snapshot capture.

components/offline_pages/snapshot_controller.cc

Index: components/offline_pages/snapshot_controller.cc
diff --git a/components/offline_pages/snapshot_controller.cc b/components/offline_pages/snapshot_controller.cc
index b086e486c34a505e5adbfb7711486d462f9ea652..374b9f561119b3fcb9feadfe97d591ae6d7c8940 100644
--- a/components/offline_pages/snapshot_controller.cc
+++ b/components/offline_pages/snapshot_controller.cc
@@ -31,6 +31,8 @@ SnapshotController::SnapshotController(
 SnapshotController::~SnapshotController() {}
 
 void SnapshotController::Reset() {
+  // Cancel potentially delayed tasks that relate to the previous 'session'.
+  weak_ptr_factory_.InvalidateWeakPtrs();
   state_ = State::kReady;
 }
 
@@ -67,8 +69,8 @@ void SnapshotController::DocumentOnLoadCompletedInMainFrame() {
 void SnapshotController::MaybeStartSnapshot() {
   if (state_ != State::kReady)
     return;
-  if (client_->StartSnapshot())
-    state_ = State::kSnapshotPending;
+  state_ = State::kSnapshotPending;
+  client_->StartSnapshot();
 }
 
 size_t SnapshotController::GetDelayAfterDocumentAvailableForTest() {