Add |needs_resize_ack| flag to ViewMsg_Resize

content/renderer/render_widget.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/renderer/render_widget.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 760 matching lines @@
   return RenderThread::Get()->Send(message);
 }
 
 void RenderWidget::Resize(const gfx::Size& new_size,
                           const gfx::Size& physical_backing_size,
                           bool top_controls_shrink_blink_size,
                           float top_controls_height,
                           const gfx::Size& visible_viewport_size,
                           const gfx::Rect& resizer_rect,
                           bool is_fullscreen,
-                          ResizeAck resize_ack) {
+                          const ResizeAck resize_ack) {
   if (resizing_mode_selector_->NeverUsesSynchronousResize()) {
     // A resize ack shouldn't be requested if we have not ACK'd the previous
     // one.
     DCHECK(resize_ack != SEND_RESIZE_ACK || !next_paint_is_resize_ack());
     DCHECK(resize_ack == SEND_RESIZE_ACK || resize_ack == NO_RESIZE_ACK);
   }
 
   // Ignore this during shutdown.
   if (!webwidget_)
     return;
@@ skipping 17 matching lines @@
   webwidget_->setTopControlsHeight(top_controls_height,
                                    top_controls_shrink_blink_size_);
 
   if (size_ != new_size) {
     size_ = new_size;
 
     // When resizing, we want to wait to paint before ACK'ing the resize.  This
     // ensures that we only resize as fast as we can paint.  We only need to
     // send an ACK if we are resized to a non-empty rect.
     webwidget_->resize(new_size);
-  } else if (!resizing_mode_selector_->is_synchronous_mode()) {

[no sievers, 2015/02/25 00:58:59]

Now I'm probably missing to make sure that resize_ack == NO_RESIZE_ACK in that
case.

[no sievers, 2015/02/25 01:11:46]

Ok, this is for webkit layout tests. So I guess I have to keep this.
And I assume this corresponds to
RenderWidgetHost::g_check_for_pending_resize_ack?

So it doesn't simplify the code as is yet. But it means it will allow us to
either
a) not do anything special for fixing the original bug I wanted to fix (but only
add logic to the browser)
b) set a sort of fake msg here to handle cases here where the browser wants an
ACK, but we are not compositing

[piman, 2015/02/25 01:38:32]

Yeah... +jochen.
It's related. I wonder if there's a way to do this nicer from the browser side.
Yes, I think it's a win as is.

-    resize_ack = NO_RESIZE_ACK;
   }
 
   webwidget()->resizePinchViewport(gfx::Size(
       visible_viewport_size.width(),
       visible_viewport_size.height()));
 
   if (new_size.IsEmpty() || physical_backing_size.IsEmpty()) {
-    // For empty size or empty physical_backing_size, there is no next paint
-    // (along with which to send the ack) until they are set to non-empty.
-    resize_ack = NO_RESIZE_ACK;
+    // In this case there is no paint/composite and therefore no
+    // ViewHostMsg_UpdateRect to send the resize ack with. We'd need to send the
+    // ack through a fake ViewHostMsg_UpdateRect or a different message.
+    DCHECK_EQ(resize_ack, NO_RESIZE_ACK);
   }
 
   // Send the Resize_ACK flag once we paint again if requested.
   if (resize_ack == SEND_RESIZE_ACK)
     set_next_paint_is_resize_ack();
 
   if (fullscreen_change)
     DidToggleFullscreen();
 
   // If a resize ack is requested and it isn't set-up, then no more resizes will
@@ skipping 62 matching lines @@
 
   screen_info_ = params.screen_info;
   SetDeviceScaleFactor(screen_info_.deviceScaleFactor);
   Resize(params.new_size,
          params.physical_backing_size,
          params.top_controls_shrink_blink_size,
          params.top_controls_height,
          params.visible_viewport_size,
          params.resizer_rect,
          params.is_fullscreen,
-         SEND_RESIZE_ACK);
+         params.needs_resize_ack ? SEND_RESIZE_ACK : NO_RESIZE_ACK);
 
   if (orientation_changed)
     OnOrientationChange();
 }
 
 void RenderWidget::OnColorProfile(const std::vector<char>& color_profile) {
   SetDeviceColorProfile(color_profile);
 }
 
 void RenderWidget::OnChangeResizeRect(const gfx::Rect& resizer_rect) {
@@ skipping 1491 matching lines @@
 void RenderWidget::RegisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.AddObserver(frame);
 }
 
 void RenderWidget::UnregisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.RemoveObserver(frame);
 }
 #endif  // defined(VIDEO_HOLE)
 
 }  // namespace content