Why this CL triggers an OilPan crash.

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index 32bfe0a1f7bd6404309540f6d3822ce589191ca1..facb9bc941b58de7dd89a31faa4a1d2a0b8c5e58 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -270,15 +270,23 @@ class ColorOverlay final : public PageOverlay::Delegate {
 
 // WebView ----------------------------------------------------------------
 
+static_assert(
+    Page::kUnknownBrowsingInstance == WebView::kUnknownBrowsingInstance,
+    "Constants should have the same value in blink's web and core layers");
+
 WebView* WebView::Create(WebViewClient* client,
-                         WebPageVisibilityState visibility_state) {
-  return WebViewImpl::Create(client, visibility_state);
+                         WebPageVisibilityState visibility_state,
+                         int browsing_instance_id) {
+  return WebViewImpl::Create(client, visibility_state, browsing_instance_id);
 }
 
 WebViewBase* WebViewImpl::Create(WebViewClient* client,
-                                 WebPageVisibilityState visibility_state) {
+                                 WebPageVisibilityState visibility_state,
+                                 int browsing_instance_id) {
   // Pass the WebViewImpl's self-reference to the caller.
-  return AdoptRef(new WebViewImpl(client, visibility_state)).LeakRef();
+  return AdoptRef(
+             new WebViewImpl(client, visibility_state, browsing_instance_id))
+      .LeakRef();
 }
 
 const WebInputEvent* WebViewBase::CurrentInputEvent() {
@@ -335,7 +343,8 @@ HashSet<WebViewBase*>& WebViewBase::AllInstances() {
 }
 
 WebViewImpl::WebViewImpl(WebViewClient* client,
-                         WebPageVisibilityState visibility_state)
+                         WebPageVisibilityState visibility_state,
+                         int browsing_instance_id)
     : client_(client),
       spell_check_client_(nullptr),
       chrome_client_impl_(ChromeClientImpl::Create(this)),
@@ -392,7 +401,7 @@ WebViewImpl::WebViewImpl(WebViewClient* client,
   page_clients.editor_client = &editor_client_impl_;
   page_clients.spell_checker_client = &spell_checker_client_impl_;
 
-  page_ = Page::CreateOrdinary(page_clients);
+  page_ = Page::CreateOrdinary(page_clients, browsing_instance_id);
   MediaKeysController::ProvideMediaKeysTo(*page_, &media_keys_client_impl_);
   ProvideSpeechRecognitionTo(
       *page_, SpeechRecognitionClientProxy::Create(