android: Migrate old content readback to use async readback (and delegated renderer)

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index c1aa70b52ef90ce1733e1576ad58885982f04060..7c263c4673f9c633dafb5c7ef67154f5f1e7da26 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -139,7 +139,7 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
     ContentViewCoreImpl* content_view_core)
     : host_(widget_host),
       needs_begin_frame_(false),
-      are_layers_attached_(!widget_host->is_hidden()),
+      is_showing_(!widget_host->is_hidden()),
       content_view_core_(NULL),
       ime_adapter_android_(this),
       cached_background_color_(SK_ColorWHITE),
@@ -259,31 +259,21 @@ void RenderWidgetHostViewAndroid::SetBounds(const gfx::Rect& rect) {
   SetSize(rect.size());
 }
 
-blink::WebGLId RenderWidgetHostViewAndroid::GetScaledContentTexture(
+void RenderWidgetHostViewAndroid::GetScaledContentBitmap(
     float scale,
-    gfx::Size* out_size) {
-  gfx::Size size(gfx::ToCeiledSize(
-      gfx::ScaleSize(texture_size_in_layer_, scale)));
-
-  if (!CompositorImpl::IsInitialized() ||
-      texture_id_in_layer_ == 0 ||
-      texture_size_in_layer_.IsEmpty() ||
-      size.IsEmpty()) {
-    if (out_size)
-        out_size->SetSize(0, 0);
-
-    return 0;
-  }
-
-  if (out_size)
-    *out_size = size;
-
-  GLHelper* helper = ImageTransportFactoryAndroid::GetInstance()->GetGLHelper();
-  return helper->CopyAndScaleTexture(texture_id_in_layer_,
-                                     texture_size_in_layer_,
-                                     size,
-                                     true,
-                                     GLHelper::SCALER_QUALITY_FAST);
+    gfx::Size* out_size,
+    const base::Callback<void(bool, const SkBitmap&)>& callback) {
+  gfx::Size bounds = layer_->bounds();
+  gfx::Rect src_subrect(bounds);
+  const gfx::Display& display =
+      gfx::Screen::GetNativeScreen()->GetPrimaryDisplay();
+  float device_scale_factor = display.device_scale_factor();
+  DCHECK_GT(device_scale_factor, 0);
+  gfx::Size dst_size(
+      gfx::ToCeiledSize(gfx::ScaleSize(bounds, scale / device_scale_factor)));
+  *out_size = dst_size;
+  view->ResetClipping();

[no sievers, 2014/01/28 20:47:21]

Not sure how this is used by the app, it's really not obvious unfortunately.
But how comes this is not a problem to reset this arbitrarily?

[powei, 2014/01/29 13:53:17]

Done.  Not affecting delegated rendering so removed.

+  CopyFromCompositingSurface(src_subrect, dst_size, callback, false);
 }
 
 bool RenderWidgetHostViewAndroid::PopulateBitmapWithContents(jobject jbitmap) {
@@ -323,6 +313,9 @@ bool RenderWidgetHostViewAndroid::PopulateBitmapWithContents(jobject jbitmap) {
 bool RenderWidgetHostViewAndroid::HasValidFrame() const {
   if (!content_view_core_)
     return false;

[no sievers, 2014/01/28 20:47:21]

nit: Can we just check for !layer_ here.

If the layer is not attached, it's not strictly an error. It just means that the
readback will be delayed until the layer gets reattached to the root.

We could allow this - it doesn't seem particularly illegal. If you are worried
that it could cause unwanted bugs, how about putting a check for that into the
app?

Can we also DCHECK(!is_showing_ || layer_) before?
Ideally even DCHECK((!is_showing_ && !is_locked_) || layer_);

[powei, 2014/01/29 13:53:17]

Done
Not quite sure what you mean here.  Why would we allow a readback without a
layer to do the readback on?

+  if (!layer_ || !layer_->parent())
+    return false;
+
   if (texture_size_in_layer_.IsEmpty())
     return false;
 
@@ -387,10 +380,10 @@ bool RenderWidgetHostViewAndroid::IsSurfaceAvailableForCopy() const {
 }
 
 void RenderWidgetHostViewAndroid::Show() {
-  if (are_layers_attached_)
+  if (is_showing_)
     return;
 
-  are_layers_attached_ = true;
+  is_showing_ = true;
   AttachLayers();

[no sievers, 2014/01/28 20:47:21]

Can this just call layer_->SetHideLayerAndSubtree(false) instead?

[powei, 2014/01/29 13:53:17]

Done.

 
   frame_evictor_->SetVisible(true);
@@ -398,11 +391,11 @@ void RenderWidgetHostViewAndroid::Show() {
 }
 
 void RenderWidgetHostViewAndroid::Hide() {
-  if (!are_layers_attached_)
+  if (!is_showing_)
     return;
 
-  are_layers_attached_ = false;
-  RemoveLayers();
+  is_showing_ = false;
+  AttachLayers();

[no sievers, 2014/01/28 20:47:21]

Can this just call layer_->SetHideLayerAndSubtree(true) instead?

[powei, 2014/01/29 13:53:17]

Done.

 
   frame_evictor_->SetVisible(false);
   WasHidden();
@@ -412,7 +405,7 @@ bool RenderWidgetHostViewAndroid::IsShowing() {
   // ContentViewCoreImpl represents the native side of the Java
   // ContentViewCore.  It being NULL means that it is not attached
   // to the View system yet, so we treat this RWHVA as hidden.
-  return are_layers_attached_ && content_view_core_;
+  return is_showing_ && content_view_core_;
 }
 
 void RenderWidgetHostViewAndroid::LockResources() {
@@ -690,6 +683,7 @@ void RenderWidgetHostViewAndroid::CopyFromCompositingSurface(
           start_time,
           callback));
   }
+
   request->set_area(src_subrect_in_pixel);
   layer_->RequestCopyOfOutput(request.Pass());
 }
@@ -739,8 +733,7 @@ void RenderWidgetHostViewAndroid::UnusedResourcesAreAvailable() {
 }
 
 void RenderWidgetHostViewAndroid::DestroyDelegatedContent() {
-  if (are_layers_attached_)
-    RemoveLayers();
+  RemoveLayers();
   frame_provider_ = NULL;
   delegated_renderer_layer_ = NULL;
   layer_ = NULL;
@@ -776,15 +769,13 @@ void RenderWidgetHostViewAndroid::SwapDelegatedFrame(
     }
     if (!frame_provider_ ||
         texture_size_in_layer_ != frame_provider_->frame_size()) {
-      if (are_layers_attached_)
-        RemoveLayers();
+      RemoveLayers();
       frame_provider_ = new cc::DelegatedFrameProvider(
           resource_collection_.get(), frame_data.Pass());
       delegated_renderer_layer_ =
           cc::DelegatedRendererLayer::Create(frame_provider_);
       layer_ = delegated_renderer_layer_;
-      if (are_layers_attached_)
-        AttachLayers();
+      AttachLayers();
     } else {
       frame_provider_->SetFrameData(frame_data.Pass());
     }
@@ -843,6 +834,7 @@ void RenderWidgetHostViewAndroid::OnSwapCompositorFrame(
     ComputeContentsSize(frame->metadata);
 
     SwapDelegatedFrame(output_surface_id, frame->delegated_frame_data.Pass());
+    frame_evictor_->SwappedFrame(!host_->is_hidden());
     return;
   }
 
@@ -995,6 +987,7 @@ void RenderWidgetHostViewAndroid::AttachLayers() {
   content_view_core_->AttachLayer(layer_);
   if (overscroll_effect_enabled_)
     overscroll_effect_->Enable();
+  layer_->SetHideLayerAndSubtree(!is_showing_);
 }
 
 void RenderWidgetHostViewAndroid::RemoveLayers() {
@@ -1326,7 +1319,7 @@ SkColor RenderWidgetHostViewAndroid::GetCachedBackgroundColor() const {
 void RenderWidgetHostViewAndroid::OnOverscrolled(
     gfx::Vector2dF accumulated_overscroll,
     gfx::Vector2dF current_fling_velocity) {
-  if (!content_view_core_ || !are_layers_attached_)
+  if (!content_view_core_ || !layer_ || !is_showing_)
     return;
 
   if (overscroll_effect_->OnOverscrolled(content_view_core_->GetLayer(),
@@ -1346,9 +1339,7 @@ void RenderWidgetHostViewAndroid::SetContentViewCore(
     ContentViewCoreImpl* content_view_core) {
   RunAckCallbacks();
 
-  if (are_layers_attached_)
-    RemoveLayers();
-
+  RemoveLayers();
   if (content_view_core_ && !using_synchronous_compositor_)
     content_view_core_->GetWindowAndroid()->RemoveObserver(this);
 
@@ -1362,11 +1353,9 @@ void RenderWidgetHostViewAndroid::SetContentViewCore(
         SetContentViewCore(obj);
   }
 
-  if (are_layers_attached_) {
-    AttachLayers();
-    if (content_view_core_ && !using_synchronous_compositor_)
-      content_view_core_->GetWindowAndroid()->AddObserver(this);
-  }
+  AttachLayers();
+  if (content_view_core_ && !using_synchronous_compositor_)
+    content_view_core_->GetWindowAndroid()->AddObserver(this);
 
   // Ensure ContentsViewCore is aware of the current touch handling state, eg.
   // in case we've already been running JS for the page as part of preload.
@@ -1413,7 +1402,6 @@ void RenderWidgetHostViewAndroid::PrepareTextureCopyOutputResult(
     const base::TimeTicks& start_time,
     const base::Callback<void(bool, const SkBitmap&)>& callback,
     scoped_ptr<cc::CopyOutputResult> result) {
-  DCHECK(result->HasTexture());

[no sievers, 2014/01/28 20:47:21]

just wondering: when is this failing?

[powei, 2014/01/29 13:53:17]

Don't have a consistent repo, but I do hit this sometimes.  I can put a TODO for
investigation if you'd prefer that.

   base::ScopedClosureRunner scoped_callback_runner(
       base::Bind(callback, false, SkBitmap()));