PlzNavigate: Invoke didStartProvisionalLoad() when the renderer initiates a navigation in startLoad(

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index f90f72cb79180c0490f90689f16dfc61b73f5469..cfd99f5f9841caacaf279766081bcfee0bd8380e 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -1737,19 +1737,35 @@ void FrameLoader::startLoad(FrameLoadRequest& frameLoadRequest,
         !frameLoadRequest.resourceRequest().checkForBrowserSideNavigation()) {
       m_isNavigationHandledByClient = false;
     }
+    DocumentLoader* loader = createDocumentLoader(
+        resourceRequest, frameLoadRequest, type, navigationType);
+    // PlzNavigate: If the navigation is handled by the client, then the
+    // didFinishDocumentLoad() event occurs before the
+    // didStartProvisionalLoad() notification which occurs after the navigation
+    // is committed. This causes a number of layout tests to fail. We
+    // workaround this by invoking the didStartProvisionalLoad() notification
+    // here. Consumers of the didStartProvisionalLoad() notification rely on
+    // the provisional loader and save navigation state in it. We want to avoid
+    // this dependency on the provisional loader. For now we create a temporary
+    // loader and pass it to the didStartProvisionalLoad() function.
+    // TODO(ananta)
+    // We should get rid of the dependency on the DocumentLoader in consumers of
+    // the didStartProvisionalLoad() notification.
+    client()->dispatchDidStartProvisionalLoad(loader);
+    DCHECK(loader);
+    loader->setSentDidFinishLoad();
+    loader->detachFromFrame();
     return;
   }
 
-  m_provisionalDocumentLoader = client()->createDocumentLoader(
-      m_frame, resourceRequest,
-      frameLoadRequest.substituteData().isValid()
-          ? frameLoadRequest.substituteData()
-          : defaultSubstituteDataForURL(resourceRequest.url()),
-      frameLoadRequest.clientRedirect());
-  m_provisionalDocumentLoader->setLoadType(type);
-  m_provisionalDocumentLoader->setNavigationType(navigationType);
-  m_provisionalDocumentLoader->setReplacesCurrentHistoryItem(
-      type == FrameLoadTypeReplaceCurrentItem);
+  m_provisionalDocumentLoader = createDocumentLoader(
+      resourceRequest, frameLoadRequest, type, navigationType);
+
+  // TODO(ananta)
+  // We should get rid of the dependency on the DocumentLoader in consumers of
+  // the didStartProvisionalLoad() notification.
+  client()->dispatchDidStartProvisionalLoad(m_provisionalDocumentLoader);
+  DCHECK(m_provisionalDocumentLoader);
 
   // PlzNavigate: We need to ensure that script initiated navigations are
   // honored.
@@ -1771,8 +1787,7 @@ void FrameLoader::startLoad(FrameLoadRequest& frameLoadRequest,
 
   m_provisionalDocumentLoader->appendRedirect(
       m_provisionalDocumentLoader->getRequest().url());
-  client()->dispatchDidStartProvisionalLoad();
-  DCHECK(m_provisionalDocumentLoader);
+
   m_provisionalDocumentLoader->startLoadingMainResource();
 
   takeObjectSnapshot();
@@ -1963,4 +1978,22 @@ inline void FrameLoader::takeObjectSnapshot() const {
                                       toTracedValue());
 }
 
+DocumentLoader* FrameLoader::createDocumentLoader(
+    const ResourceRequest& request,
+    const FrameLoadRequest& frameLoadRequest,
+    FrameLoadType loadType,
+    NavigationType navigationType) {
+  DocumentLoader* loader = client()->createDocumentLoader(
+      m_frame, request, frameLoadRequest.substituteData().isValid()
+                            ? frameLoadRequest.substituteData()
+                            : defaultSubstituteDataForURL(request.url()),
+      frameLoadRequest.clientRedirect());
+
+  loader->setLoadType(loadType);
+  loader->setNavigationType(navigationType);
+  loader->setReplacesCurrentHistoryItem(loadType ==
+                                        FrameLoadTypeReplaceCurrentItem);
+  return loader;
+}
+
 }  // namespace blink