Support tracking focused element for OOPIFs.

content/browser/renderer_host/render_widget_host_view_aura.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/renderer_host/render_widget_host_view_aura.h"
 
 #include <set>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 170 matching lines @@
         return;
 
       host_->GetView()->SetInsets(gfx::Insets(0, 0, viewport_bottom, 0));
 
       gfx::Point origin(location_in_screen_);
       screen_position_client->ConvertPointFromScreen(window_, &origin);
 
       // We want to scroll the node into a rectangle which originates from
       // the touch point and a small offset (10) in either direction.
       gfx::Rect node_rect(origin.x(), origin.y(), 10, 10);
       host_->ScrollFocusedEditableNodeIntoRect(node_rect);

[EhsanK, 2016/12/20 16:39:11]

This is the spot which needs to get fixed. Since we work on focused frame (i.e.,
focused element is in focused frame), getting the right widget is easy with
RenderWidgetHostDelegate::GetFocusedRenderWidgetHost().

However, just doing that does not fix the issue (i.e., tapping the <input> in an
OOPIF does not do the right scrolling (up) thing.

I think we need to add another method to first scroll the corresponding <iframe>
up in the middle or top of the screen. This should happen in OOPIF's parent's
process. Then calling this on the focused widget will hopefully bring up the
<input> properly.

     }
   }
 
   void OnKeyboardHidden(const gfx::Rect& keyboard_rect_pixels) override {
     // Restore the viewport.
     host_->GetView()->SetInsets(gfx::Insets());
   }
 
  private:
   RenderWidgetHostImpl* host_;
@@ skipping 584 matching lines @@
     const gfx::Point& location_dips_screen,
     bool editable) {
 #if defined(OS_WIN)
   RenderViewHost* rvh = RenderViewHost::From(host_);
   if (rvh && rvh->GetDelegate())
     rvh->GetDelegate()->SetIsVirtualKeyboardRequested(editable);
 
   ui::OnScreenKeyboardDisplayManager* osk_display_manager =
       ui::OnScreenKeyboardDisplayManager::GetInstance();
   DCHECK(osk_display_manager);
-  if (editable && host_ && host_->GetView()) {
+  if (editable && host_ && host_->GetView() && host_->delegate()) {
+    RenderWidgetHostImpl* host =
+        host_->delegate()->GetFocusedRenderWidgetHost(host_);
     keyboard_observer_.reset(new WinScreenKeyboardObserver(
-        host_, location_dips_screen, device_scale_factor_, window_));
+        host, location_dips_screen, device_scale_factor_, window_));

[ncarter (slow), 2016/12/16 19:17:21]

I'm thinking about the case here where (host_ != host), and the layering looks a
little odd.

Doesn't |host| have its own RWHView? It seems kind of strange for RWHVAura to
provide this service to other RWHs, and to have a |keyboard_observer_| member
that holds a pointer to the other |host|.

Among other things, I worry about:
 - what prevents the |host| pointer passed to WinScreenKeyboardObserver from
becoming invalid in the oopif case, if, say, it's an oopif widget whose FTN is
destroyed by a navigation?
 - When WinScreenKeyboardObserver calls SetInsets on |host|, and host is an
oopif widget, does the right thing happen? It seems like we want to adjust
insets on the outer RWHVAura, not the inner RWHVChildFrame.

[EhsanK, 2016/12/20 16:39:11]

Agreed. It is probably actually incorrect.
I think given that this is a page thing, RWHVAura should be a good place for
keeping keyboard reference. But |host| should not be that of a child frame.
Unfortunately nothing. If the RenderFrame goes out normally, we get a focused
node changed which will reset this. But I tested a case where I crashed the
renderer and this caused a browser crash.
I think (frome the comments in render_widget_host_view.h) this method should
only be called on page level view. So I should actually pass the old |host_|
instead of |host|.

But the scrolling for focused node will be broken and that needs extra fixes
that I am working on now. I left a comment above where the change should occur.

     virtual_keyboard_requested_ =
         osk_display_manager->DisplayVirtualKeyboard(keyboard_observer_.get());
   } else {
     virtual_keyboard_requested_ = false;
     osk_display_manager->DismissVirtualKeyboard();
   }
 #endif
 }
 
 void RenderWidgetHostViewAura::UpdateCursor(const WebCursor& cursor) {
@@ skipping 1585 matching lines @@
 
 void RenderWidgetHostViewAura::SetPopupChild(
     RenderWidgetHostViewAura* popup_child_host_view) {
   popup_child_host_view_ = popup_child_host_view;
   event_handler_->SetPopupChild(
       popup_child_host_view,
       popup_child_host_view ? popup_child_host_view->event_handler() : nullptr);
 }
 
 }  // namespace content