Mark WebViewClient subclasses that return a null layerTreeView.

In a followup blink-side patch, returning a null layerTreeView without
returning true from allowsBrokenNullLayerTreeView will assert.
Soon, we'll delete the null layerTreeView codepath entirely.
This is to make sure we have all the cases identified and so
that new ones don't get added.

Remove the null-check in RenderWidget::initializeLayerTreeView.
It never sets compositor_ to null and on the blink side we
assert as such.

Review URL: https://codereview.chromium.org/242953005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@265252 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 26 insertions, 3 deletions

diff --git a/android_webview/renderer/print_web_view_helper.cc b/android_webview/renderer/print_web_view_helper.cc
index b9d38fd4..006a371 100644
--- a/android_webview/renderer/print_web_view_helper.cc
+++ b/android_webview/renderer/print_web_view_helper.cc
@@ -537,6 +537,11 @@ class PrepareFrameAndViewForPrint : public blink::WebViewClient,
     return owns_web_view_ && frame() && frame()->isLoading();
   }
 
+  // TODO(ojan): Remove this override and have this class use a non-null
+  // layerTreeView.
+  // blink::WebViewClient override:
+  virtual bool allowsBrokenNullLayerTreeView() const;
+
  protected:
   // blink::WebViewClient override:
   virtual void didStopLoading();
@@ -671,6 +676,10 @@ void PrepareFrameAndViewForPrint::CopySelection(
   frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
 }
 
+bool PrepareFrameAndViewForPrint::allowsBrokenNullLayerTreeView() const {
+  return true;
+}
+
 void PrepareFrameAndViewForPrint::didStopLoading() {
   DCHECK(!on_ready_.is_null());
   // Don't call callback here, because it can delete |this| and WebView that is
diff --git a/chrome/renderer/printing/print_web_view_helper.cc b/chrome/renderer/printing/print_web_view_helper.cc
index 2f75442..259601e 100644
--- a/chrome/renderer/printing/print_web_view_helper.cc
+++ b/chrome/renderer/printing/print_web_view_helper.cc
@@ -566,6 +566,11 @@ class PrepareFrameAndViewForPrint : public blink::WebViewClient,
     return owns_web_view_ && frame() && frame()->isLoading();
   }
 
+  // TODO(ojan): Remove this override and have this class use a non-null
+  // layerTreeView.
+  // blink::WebViewClient override:
+  virtual bool allowsBrokenNullLayerTreeView() const;
+
  protected:
   // blink::WebViewClient override:
   virtual void didStopLoading();
@@ -701,6 +706,10 @@ void PrepareFrameAndViewForPrint::CopySelection(
   frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
 }
 
+bool PrepareFrameAndViewForPrint::allowsBrokenNullLayerTreeView() const {
+  return true;
+}
+
 void PrepareFrameAndViewForPrint::didStopLoading() {
   DCHECK(!on_ready_.is_null());
   // Don't call callback here, because it can delete |this| and WebView that is
diff --git a/components/plugins/renderer/webview_plugin.cc b/components/plugins/renderer/webview_plugin.cc
index 6095e2b..b1df67c 100644
--- a/components/plugins/renderer/webview_plugin.cc
+++ b/components/plugins/renderer/webview_plugin.cc
@@ -219,6 +219,10 @@ void WebViewPlugin::startDragging(WebLocalFrame*,
   web_view_->dragSourceSystemDragEnded();
 }
 
+bool WebViewPlugin::allowsBrokenNullLayerTreeView() const {
+  return true;
+}
+
 void WebViewPlugin::didInvalidateRect(const WebRect& rect) {
   if (container_)
     container_->invalidateRect(rect);
diff --git a/components/plugins/renderer/webview_plugin.h b/components/plugins/renderer/webview_plugin.h
index af352ec..8c17c51 100644
--- a/components/plugins/renderer/webview_plugin.h
+++ b/components/plugins/renderer/webview_plugin.h
@@ -116,6 +116,10 @@ class WebViewPlugin : public blink::WebPlugin,
                              const blink::WebImage& image,
                              const blink::WebPoint& point);
 
+  // TODO(ojan): Remove this override and have this class use a non-null
+  // layerTreeView.
+  virtual bool allowsBrokenNullLayerTreeView() const;
+
   // WebWidgetClient methods:
   virtual void didInvalidateRect(const blink::WebRect&);
   virtual void didChangeCursor(const blink::WebCursorInfo& cursor);
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 3a156f3..e126a3f 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -1558,9 +1558,6 @@ void RenderWidget::didDeactivateCompositor() {
 void RenderWidget::initializeLayerTreeView() {
   compositor_ = RenderWidgetCompositor::Create(
       this, is_threaded_compositing_enabled_);
-  if (!compositor_)
-    return;
-
   compositor_->setViewportSize(size_, physical_backing_size_);
   if (init_complete_)
     StartCompositor();