[Sync] Adding revisit logic for typed URLs.

components/sync_sessions/revisit/typed_url_page_revisit_task.cc

Index: components/sync_sessions/revisit/typed_url_page_revisit_task.cc
diff --git a/components/sync_sessions/revisit/typed_url_page_revisit_task.cc b/components/sync_sessions/revisit/typed_url_page_revisit_task.cc
new file mode 100644
index 0000000000000000000000000000000000000000..240cdc3c45fa8b95ce9facc4993bf7bb9a158545
--- /dev/null
+++ b/components/sync_sessions/revisit/typed_url_page_revisit_task.cc
@@ -0,0 +1,76 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/sync_sessions/revisit/typed_url_page_revisit_task.h"
+
+#include "base/metrics/histogram_macros.h"
+#include "base/time/time.h"
+#include "components/history/core/browser/history_backend.h"
+#include "components/history/core/browser/history_service.h"
+#include "components/history/core/browser/url_row.h"
+
+namespace sync_sessions {
+
+TypedUrlPageRevisitTask::TypedUrlPageRevisitTask(
+    const GURL& url,
+    const PageVisitObserver::TransitionType transition)
+    : url_(url), transition_(transition) {}
+
+TypedUrlPageRevisitTask::~TypedUrlPageRevisitTask() {}
+
+bool TypedUrlPageRevisitTask::FillVisitsAndSources(
+    history::HistoryBackend* backend,

[stanisc, 2015/10/13 21:53:33]

Should HistoryBackend* be a const pointer?

[skym, 2015/10/13 22:25:14]

We could do "history::HistoryBackend* const backend" I think, but I'm assuming
you're asking about "const history::HistoryBackend* backend", which we cannot
do. Pretty much all the methods on HistoryBackend are non-const, which seems to
be because all the backing DB implementation functions are also non-const.

+    history::VisitVector* visits,
+    history::VisitSourceMap* sources) {
+  history::URLRow row;
+  return backend->GetURL(url_, &row) &&
+         backend->GetVisitsForURL(row.id(), visits) &&
+         backend->GetVisitsSource(*visits, sources);
+}
+
+bool TypedUrlPageRevisitTask::FindLastSyncedMatchAge(
+    history::HistoryBackend* backend,
+    base::Time* lastVisitTime) {
+  history::VisitVector visits;
+  history::VisitSourceMap sources;
+  if (FillVisitsAndSources(backend, &visits, &sources)) {
+    // The visits are in chronological order. We only care about the most
+    // recent remote visit, so iterate backwards.
+    for (auto row_itr = visits.rbegin(); row_itr != visits.rend(); ++row_itr) {
+      auto map_itr = sources.find(row_itr->visit_id);
+      if (map_itr != sources.end() &&
+          map_itr->second == history::SOURCE_SYNCED) {
+        *lastVisitTime = row_itr->visit_time;
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+bool TypedUrlPageRevisitTask::RunOnDBThread(history::HistoryBackend* backend,
+                                            history::HistoryDatabase* db) {
+  base::TimeTicks start(base::TimeTicks::Now());
+  base::Time lastVisitTime;
+  if (FindLastSyncedMatchAge(backend, &lastVisitTime)) {
+    REVISIT_HISTOGRAM_AGE("Sync.PageRevisitTypedUrlMatchAge", lastVisitTime);
+    UMA_HISTOGRAM_ENUMERATION("Sync.PageRevisitTypedUrlMatchTransition",
+                              transition_,
+                              PageVisitObserver::kTransitionTypeLast);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION("Sync.PageRevisitTypedUrlMissTransition",
+                              transition_,
+                              PageVisitObserver::kTransitionTypeLast);
+  }
+
+  base::TimeDelta duration(base::TimeTicks::Now() - start);
+  UMA_HISTOGRAM_TIMES("Sync.PageRevisitTypedUrlDuration", duration);
+
+  // This indicates success and retring is not needed.
+  return true;
+}
+
+void TypedUrlPageRevisitTask::DoneRunOnMainThread() {}
+
+}  // namespace sync_sessions