Propagate auto-resize viewport values to OOPIF processes

content/browser/web_contents/web_contents_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 2768 matching lines @@
   preferred_size_ = pref_size;
   OnPreferredSizeChanged(old_size);
 }
 
 void WebContentsImpl::ResizeDueToAutoResize(
     RenderWidgetHostImpl* render_widget_host,
     const gfx::Size& new_size) {
   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()) {
+    if (node->current_frame_host()->is_local_root()) {
+      RenderWidgetHostImpl* host =
+          node->current_frame_host()->GetRenderWidgetHost();
+      if (host != render_widget_host)
+        host->SendScreenRects();

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

Just to make sure I understand: how does this end up using |new_size|? 
SendScreenRects() seems to send  GetViewBounds() and GetBoundsInRootWindow() -
do those end up depending on the auto-resize size and querying
GetAutoResizeSize() somehow?

[kenrb, 2017/06/02 17:23:27]

Good catch, thanks, this is wrong. I had mistakenly thought that there was
SendScreenRects also activated the RWHI resize path, but it doesn't. The fact
that it worked was probably a fluke, that auto-size was always getting activated
early enough for this not to matter.

Now corrected.

+    }
+  }
+
   if (delegate_)
     delegate_->ResizeDueToAutoResize(this, new_size);
 }
 
+gfx::Size WebContentsImpl::GetAutoResizeSize() {
+  return auto_resize_size_;
+}
+
 WebContents* WebContentsImpl::OpenURL(const OpenURLParams& params) {
   if (!delegate_)
     return NULL;
 
   WebContents* new_contents = delegate_->OpenURLFromTab(this, params);
 
   RenderFrameHost* source_render_frame_host = RenderFrameHost::FromID(
       params.source_render_process_id, params.source_render_frame_id);
 
   if (source_render_frame_host && params.source_site_instance) {
@@ skipping 2850 matching lines @@
     RenderViewHost* render_view_host = RenderViewHost::From(render_widget_host);
     if (!render_view_host)
       continue;
     render_view_host_set.insert(render_view_host);
   }
   for (RenderViewHost* render_view_host : render_view_host_set)
     render_view_host->OnWebkitPreferencesChanged();
 }
 
 }  // namespace content