Propagate auto-resize viewport values to OOPIF processes

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index ed882eff1d6c293bf29985766f4031d368b948c8..e2e7c50965f7278c35bc4f0d901be2e647109d7f 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -2786,10 +2786,28 @@ void WebContentsImpl::ResizeDueToAutoResize(
   if (render_widget_host != GetRenderViewHost()->GetWidget())
     return;
 
+  auto_resize_size_ = new_size;
+
+  // Out-of-process iframe visible viewport sizes usually come from the
+  // top-level RenderWidgetHostView, but when auto-resize is enabled on the
+  // top frame then that size is used instead.
+  for (FrameTreeNode* node : frame_tree_.Nodes()) {

[alexmos, 2017/06/02 00:45:22]

If any of the nodes correspond to OOPIF <webview>'s, do we need to descend down
into the inner WebContents as well?  (If yes, it's fine to leave a TODO for now
and look into that in a followup.)

[kenrb, 2017/06/02 15:44:47]

I looked at this briefly yesterday when writing this patch. GuestViews shouldn't
really be embedded within auto-resizing frames, which in general are special
dialogs or popups. The <webview> API has its own auto-resize capability, which
is not relevant here. If for some reason there was a case where <webview> was
within an auto-resizing view, I think this should just work, because the RWHVCF
for the <webview> should get the size off the top-level WebContentsImpl.

[alexmos, 2017/06/02 17:03:18]

Acknowledged.

+    if (node->current_frame_host()->is_local_root()) {
+      RenderWidgetHostImpl* host =
+          node->current_frame_host()->GetRenderWidgetHost();
+      if (host != render_widget_host)
+        host->SendScreenRects();
+    }
+  }
+
   if (delegate_)
     delegate_->ResizeDueToAutoResize(this, new_size);
 }
 
+gfx::Size WebContentsImpl::GetAutoResizeSize() {
+  return auto_resize_size_;

[alexmos, 2017/06/02 00:45:22]

Can auto-resize ever be disabled, and if so, do we need to clear this at that
point?  Otherwise, I'm wondering if we end up using this for OOPIFs even after
auto-resize is turned off.

[kenrb, 2017/06/02 15:44:47]

The answer to your question is actually no, only <webview> auto-resize is ever
disabled, which isn't affected by this CL, but after thinking about it, I think
I want to cover it anyway.

I have made a change to RenderViewHostImpl::DisableAutoResize() that clears the
cached value in WebContents. This should future-proof this, because if we do
something like try to support OOPIFs within <webview>, it would be needed.

+}
+
 WebContents* WebContentsImpl::OpenURL(const OpenURLParams& params) {
   if (!delegate_)
     return NULL;