Proof of concept implementation of context based history filtering.

components/history/core/browser/history_backend.cc

Index: components/history/core/browser/history_backend.cc
diff --git a/components/history/core/browser/history_backend.cc b/components/history/core/browser/history_backend.cc
index faf00c6db8293356065862bd9fdc5e72a72ba4c8..2194c27d3cadc06573fd05ce6d0f716588563335 100644
--- a/components/history/core/browser/history_backend.cc
+++ b/components/history/core/browser/history_backend.cc
@@ -891,6 +891,58 @@ void HistoryBackend::SetPageTitle(const GURL& url,
   }
 }
 
+void HistoryBackend::SetPageHistoryContext(const GURL& url,
+                                  HistoryContext context) {
+  if (!db_)
+    return;
+
+  // Search for recent redirects which should get the same title. We make a
+  // dummy list containing the exact URL visited if there are no redirects so
+  // the processing below can be the same.
+  RedirectList dummy_list;
+  RedirectList* redirects;
+  RedirectCache::iterator iter = recent_redirects_.Get(url);
+  if (iter != recent_redirects_.end()) {
+    redirects = &iter->second;
+
+    // This redirect chain should have the destination URL as the last item.
+    DCHECK(!redirects->empty());
+    DCHECK(redirects->back() == url);
+  } else {
+    // No redirect chain stored, make up one containing the URL we want so we
+    // can use the same logic below.
+    dummy_list.push_back(url);
+    redirects = &dummy_list;
+  }
+
+  URLRows changed_urls;
+  for (size_t i = 0; i < redirects->size(); i++) {
+    URLRow row;
+    URLID row_id = db_->GetRowForURL(redirects->at(i), &row);
+    VisitID cur_visit = db_->GetMostRecentVisitForURL(row_id, nullptr);
+    if (row_id && row.context() != context) {
+      row.set_context(context);
+
+    VisitRow visit_row;
+    if (db_->GetRowForVisit(cur_visit, &visit_row)) {
+      visit_row.context = context;
+      db_->UpdateVisitRow(visit_row);
+    printf("\n1 HistoryBackend::SetPageHistoryContext %d\n", static_cast<int>(context));
+    }
+      db_->UpdateURLRow(row_id, row);
+    printf("\n2 HistoryBackend::SetPageHistoryContext %d\n", static_cast<int>(context));
+      changed_urls.push_back(row);
+    }
+  }
+
+  // Broadcast notifications for any URLs that have changed. This will
+  // update the in-memory database and the InMemoryURLIndex.
+  if (!changed_urls.empty()) {
+    NotifyURLsModified(changed_urls);
+    ScheduleCommit();
+  }
+}
+
 void HistoryBackend::AddPageNoVisitForBookmark(const GURL& url,
                                                const base::string16& title) {
   if (!db_)