Do not reset ManifestManager state for same page navigation.

content/renderer/manifest/manifest_manager.cc

Index: content/renderer/manifest/manifest_manager.cc
diff --git a/content/renderer/manifest/manifest_manager.cc b/content/renderer/manifest/manifest_manager.cc
index a5ee94cf6b59c4d7829d5373c93b434b7f677dcc..98e976e2c2c1117d44f8f494bc74dd97338f89cf 100644
--- a/content/renderer/manifest/manifest_manager.cc
+++ b/content/renderer/manifest/manifest_manager.cc
@@ -7,6 +7,8 @@
 #include "base/bind.h"
 #include "base/strings/nullable_string16.h"
 #include "content/common/manifest_manager_messages.h"
+#include "content/public/renderer/document_state.h"
+#include "content/public/renderer/navigation_state.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/renderer/fetchers/manifest_fetcher.h"
 #include "content/renderer/manifest/manifest_parser.h"
@@ -102,6 +104,11 @@ void ManifestManager::DidChangeManifest() {
 }
 
 void ManifestManager::DidCommitProvisionalLoad(bool is_new_navigation) {
+  NavigationState* navigation_state = DocumentState::FromDataSource(
+        render_frame()->GetWebFrame()->dataSource())->navigation_state();
+  if (navigation_state->was_within_same_page())
+    return;
+
   may_have_manifest_ = false;
   manifest_dirty_ = true;
 }