Add pause/resume functionality to precache

components/precache/core/precache_database.cc

Index: components/precache/core/precache_database.cc
diff --git a/components/precache/core/precache_database.cc b/components/precache/core/precache_database.cc
index c6362fe3c226c8da6ed82fe4e5c97711292ca7c3..e9d53ecad16d8bc30ebd4415013430d1bd131dda 100644
--- a/components/precache/core/precache_database.cc
+++ b/components/precache/core/precache_database.cc
@@ -12,6 +12,7 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/history/core/browser/history_constants.h"
+#include "components/precache/core/proto/unfinished_work.pb.h"
 #include "sql/connection.h"
 #include "sql/transaction.h"
 #include "url/gurl.h"
@@ -51,7 +52,8 @@ bool PrecacheDatabase::Init(const base::FilePath& db_path) {
     return false;
   }
 
-  if (!precache_url_table_.Init(db_.get())) {
+  if (!precache_url_table_.Init(db_.get()) ||
+      !precache_session_table_.Init(db_.get())) {
     // Raze and close the database connection to indicate that it's not usable,
     // and so that the database will be created anew next time, in case it's
     // corrupted.
@@ -259,4 +261,26 @@ void PrecacheDatabase::MaybePostFlush() {
   is_flush_posted_ = true;
 }
 
+std::unique_ptr<PrecacheUnfinishedWork>
+PrecacheDatabase::GetUnfinishedWork() {
+  std::unique_ptr<PrecacheUnfinishedWork> unfinished_work =
+      precache_session_table_.GetUnfinishedWork();
+  precache_session_table_.DeleteUnfinishedWork();
+  return unfinished_work;
+}
+
+void PrecacheDatabase::SaveUnfinishedWork(
+    std::unique_ptr<PrecacheUnfinishedWork> unfinished_work) {
+  precache_session_table_.SaveUnfinishedWork(
+      std::move(unfinished_work));
+}
+
+void PrecacheDatabase::DeleteUnfinishedWork() {
+  precache_session_table_.DeleteUnfinishedWork();
+}
+
+base::WeakPtr<PrecacheDatabase> PrecacheDatabase::GetWeakPtr() {
+  return weak_factory_.GetWeakPtr();
+}
+
 }  // namespace precache