Add hooks for capturing meaningful text info, gently.

The two hooks are:
* WebLocalFrame::isNavigationPending
* WebViewClient::didFirstLayoutAfterFinishedParsing

The WebLocalFrame::isNavigationPending provides a
simple check whether the content of the document intends to
change the location (via Refresh or window.location change).

The WebViewClient::didFirstLayoutAfterFinishedParsing is called
when we finish the first layout after the document had finished
parsing. Another way to explain it is "first layout after
DOMContentLoaded".

BUG=521149
R=esprehn

Review URL: https://codereview.chromium.org/1309883003

git-svn-id: svn://svn.chromium.org/blink/trunk@201042 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/dom/Document.h

@@ -569,6 +569,7 @@ public:
     void setParsingState(ParsingState);
     bool parsing() const { return m_parsingState == Parsing; }
     bool isInDOMContentLoaded() const { return m_parsingState == InDOMContentLoaded; }
+    bool hasFinishedParsing() const { return m_parsingState == FinishedParsing; }
 
     bool shouldScheduleLayout() const;
     int elapsedTime() const;

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

@@ -158,6 +158,7 @@ public:
         request.setClientRedirect(ClientRedirect);
         frame->loader().load(request);
     }
+
 private:
     ScheduledRedirect(double delay, Document* originDocument, const String& url, bool replacesCurrentItem)
         : ScheduledURLNavigation(delay, originDocument, url, replacesCurrentItem, false)
@@ -279,6 +280,11 @@ bool NavigationScheduler::locationChangePending()
     return m_redirect && m_redirect->isLocationChange();
 }
 
+bool NavigationScheduler::isNavigationScheduled() const
+{
+    return m_redirect;
+}
+
 inline bool NavigationScheduler::shouldScheduleReload() const
 {
     return m_frame->page() && isFrameNavigationAllowed() && NavigationDisablerForBeforeUnload::isNavigationAllowed();

third_party/WebKit/Source/core/loader/NavigationScheduler.h

@@ -90,6 +90,7 @@ public:
     ~NavigationScheduler();
 
     bool locationChangePending();
+    bool isNavigationScheduled() const;
 
     void scheduleRedirect(double delay, const String& url);
     void scheduleLocationChange(Document*, const String& url, bool replacesCurrentItem = true);

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

@@ -2116,6 +2116,11 @@ bool WebLocalFrameImpl::isResourceLoadInProgress() const
     return frame()->document()->fetcher()->requestCount();
 }
 
+bool WebLocalFrameImpl::isNavigationScheduled() const
+{
+    return frame() && frame()->navigationScheduler().isNavigationScheduled();
+}
+
 void WebLocalFrameImpl::setCommittedFirstRealLoad()
 {
     ASSERT(frame());

third_party/WebKit/Source/web/WebLocalFrameImpl.h

@@ -246,6 +246,7 @@ public:
         WebHistoryLoadType) override;
     bool isLoading() const override;
     bool isResourceLoadInProgress() const override;
+    bool isNavigationScheduled() const override;
     void setCommittedFirstRealLoad() override;
     void sendOrientationChangeEvent() override;
     void willShowInstallBannerPrompt(int requestId, const WebVector<WebString>& platforms, WebAppBannerPromptReply*) override;

third_party/WebKit/Source/web/WebViewImpl.cpp

@@ -454,6 +454,7 @@ WebViewImpl::WebViewImpl(WebViewClient* client)
     , m_zoomFactorOverride(0)
     , m_userGestureObserved(false)
     , m_shouldDispatchFirstVisuallyNonEmptyLayout(false)
+    , m_shouldDispatchFirstLayoutAfterFinishedParsing(false)
     , m_displayMode(WebDisplayModeBrowser)
     , m_elasticOverscroll(FloatSize())
 {
@@ -1899,11 +1900,19 @@ void WebViewImpl::layout()
         m_linkHighlights[i]->updateGeometry();
 
     if (FrameView* view = mainFrameImpl()->frameView()) {
+        LocalFrame* frame = mainFrameImpl()->frame();
+
         if (m_shouldDispatchFirstVisuallyNonEmptyLayout && view->isVisuallyNonEmpty()) {
             m_shouldDispatchFirstVisuallyNonEmptyLayout = false;
             // TODO(esprehn): Move users of this callback to something
             // better, the heuristic for "visually non-empty" is bad.
-            mainFrameImpl()->frame()->loader().client()->dispatchDidFirstVisuallyNonEmptyLayout();
+            // TODO(dglazkov): This should likely be a WebViewClient API.
+            frame->loader().client()->dispatchDidFirstVisuallyNonEmptyLayout();
+        }
+
+        if (m_shouldDispatchFirstLayoutAfterFinishedParsing && frame->document()->hasFinishedParsing())  {
+            m_shouldDispatchFirstLayoutAfterFinishedParsing = false;
+            client()->didFirstLayoutAfterFinishedParsing();
         }
     }
 }
@@ -4099,6 +4108,7 @@ void WebViewImpl::setRootGraphicsLayer(GraphicsLayer* layer)
         m_layerTreeView->setDeferCommits(true);
         m_layerTreeView->clearRootLayer();
         m_shouldDispatchFirstVisuallyNonEmptyLayout = true;
+        m_shouldDispatchFirstLayoutAfterFinishedParsing = true;
         page()->frameHost().visualViewport().clearLayersForTreeView(m_layerTreeView);
     }
 

third_party/WebKit/Source/web/WebViewImpl.h

@@ -761,6 +761,7 @@ private:
 
     bool m_userGestureObserved;
     bool m_shouldDispatchFirstVisuallyNonEmptyLayout;
+    bool m_shouldDispatchFirstLayoutAfterFinishedParsing;
     WebDisplayMode m_displayMode;
 
     FloatSize m_elasticOverscroll;

third_party/WebKit/public/web/WebLocalFrame.h

@@ -91,6 +91,17 @@ public:
     // instead.
     virtual bool isResourceLoadInProgress() const = 0;
 
+    // Returns true if there is a pending redirect or location change.
+    // This could be caused by:
+    // * an HTTP Refresh header
+    // * an X-Frame-Options header
+    // * the respective http-equiv meta tags
+    // * window.location value being mutated
+    // * CSP policy block
+    // * reload
+    // * form submission
+    virtual bool isNavigationScheduled() const = 0;
+
     // Override the normal rules for whether a load has successfully committed
     // in this frame. Used to propagate state when this frame has navigated
     // cross process.

third_party/WebKit/public/web/WebViewClient.h

@@ -196,6 +196,10 @@ public:
     // unless the view did not need a layout.
     virtual void didUpdateLayout() { }
 
+    // The frame's document finished layout immediately after the parsing finished.
+    // Another way to put it: first frame after DOMContentLoaded is dispatched.
+    virtual void didFirstLayoutAfterFinishedParsing() { }
+
     // Return true to swallow the input event if the embedder will start a disambiguation popup
     virtual bool didTapMultipleTargets(const WebSize& pinchViewportOffset, const WebRect& touchRect, const WebVector<WebRect>& targetRects) { return false; }