Remove renderer-side tracking of accelerated compositing

content/renderer/render_widget_fullscreen_pepper.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_fullscreen_pepper.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 306 matching lines @@
   Release();
 }
 
 void RenderWidgetFullscreenPepper::DidChangeCursor(
     const blink::WebCursorInfo& cursor) {
   didChangeCursor(cursor);
 }
 
 void RenderWidgetFullscreenPepper::SetLayer(blink::WebLayer* layer) {
   layer_ = layer;
-  bool compositing = !!layer_;
-  if (compositing != is_accelerated_compositing_active_) {
-    if (compositing) {
-      if (!layerTreeView())
-        initializeLayerTreeView();
-      if (!layerTreeView())
-        return;
-      layer_->setBounds(blink::WebSize(size()));
-      layer_->setDrawsContent(true);
-      compositor_->setDeviceScaleFactor(device_scale_factor_);
-      compositor_->setRootLayer(*layer_);
-      didActivateCompositor();
-    } else {
-      didDeactivateCompositor();
-    }
-  }
+  if (!layer_)

[danakj, 2014/05/14 15:03:34]

Should we setRootLayer(NULL) if !layer_? Before we would have told the browser
we left compositing which would do things like say "there's no surface to copy
from" for a readback and stuff, now it might continue showing the old content
instead of nothing?

[enne (OOO), 2014/05/15 20:51:15]

Sure.  I think that seems reasonable, although I think it didn't do that before.

+    return;
+  if (!layerTreeView())
+    initializeLayerTreeView();
+  if (!layerTreeView())

[danakj, 2014/05/14 15:03:34]

Can this go away too?

[enne (OOO), 2014/05/15 20:51:15]

Done.

+    return;
+  layer_->setBounds(blink::WebSize(size()));
+  layer_->setDrawsContent(true);
+  compositor_->setDeviceScaleFactor(device_scale_factor_);
+  compositor_->setRootLayer(*layer_);
 }
 
 bool RenderWidgetFullscreenPepper::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RenderWidgetFullscreenPepper, msg)
     IPC_MESSAGE_FORWARD(ViewMsg_LockMouse_ACK,
                         mouse_lock_dispatcher_.get(),
                         MouseLockDispatcher::OnLockMouseACK)
     IPC_MESSAGE_FORWARD(ViewMsg_MouseLockLost,
                         mouse_lock_dispatcher_.get(),
@@ skipping 42 matching lines @@
 }
 
 void RenderWidgetFullscreenPepper::SetDeviceScaleFactor(
     float device_scale_factor) {
   RenderWidget::SetDeviceScaleFactor(device_scale_factor);
   if (compositor_)
     compositor_->setDeviceScaleFactor(device_scale_factor);
 }
 
 }  // namespace content