android: Use hw acceleration in android_webview_shell

android_webview/browser/hardware_renderer.cc

 // Copyright 2014 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 "android_webview/browser/hardware_renderer.h"
 
 #include "android_webview/browser/aw_gl_surface.h"
 #include "android_webview/browser/deferred_gpu_command_service.h"
 #include "android_webview/browser/parent_output_surface.h"
 #include "android_webview/browser/shared_renderer_state.h"
@@ skipping 168 matching lines @@
       delegated_layer_ = cc::DelegatedRendererLayer::Create(frame_provider_);
       delegated_layer_->SetBounds(gfx::Size(input->width, input->height));
       delegated_layer_->SetIsDrawable(true);
 
       root_layer_->AddChild(delegated_layer_);
     } else {
       frame_provider_->SetFrameData(input->frame.delegated_frame_data.Pass());
     }
   }
 
+  if (!delegated_layer_) {
+    LOG(INFO) << "no layer";

[no sievers, 2014/07/22 20:53:17]

The SurfaceView might start drawing before the child ever produced a frame.
Can probably inhibit the draw at a higher level instead.

+    return;
+  }
   viewport_.SetSize(draw_info->width, draw_info->height);
   layer_tree_host_->SetViewportSize(viewport_);
   clip_.SetRect(draw_info->clip_left,
                 draw_info->clip_top,
                 draw_info->clip_right - draw_info->clip_left,
                 draw_info->clip_bottom - draw_info->clip_top);
   stencil_enabled_ = stencil_enabled;
 
   gfx::Transform transform(gfx::Transform::kSkipInitialization);
   transform.matrix().setColMajorf(draw_info->transform);
-  transform.Translate(scroll_offset_.x(), scroll_offset_.y());
+//  transform.Translate(scroll_offset_.x(), scroll_offset_.y());

[no sievers, 2014/07/22 21:00:36]

So here I don't understand why we scroll in the parent compositor and not in the
child. It actually causes problems in this setup.

+  DCHECK(delegated_layer_.get());
   delegated_layer_->SetTransform(transform);
 
   gl_surface_->SetBackingFrameBufferObject(framebuffer_binding_ext);
   {
     base::AutoReset<bool> frame_resetter(&viewport_clip_valid_for_dcheck_,
                                          true);
     layer_tree_host_->SetNeedsRedrawRect(clip_);
     layer_tree_host_->Composite(gfx::FrameTime::Now());
   }
+  DCHECK(gl_surface_.get());
   gl_surface_->ResetBackingFrameBufferObject();
 }
 
 scoped_ptr<cc::OutputSurface> HardwareRenderer::CreateOutputSurface(
     bool fallback) {
   // Android webview does not support losing output surface.
   DCHECK(!fallback);
   scoped_refptr<cc::ContextProvider> context_provider =
       CreateContext(gl_surface_,
                     DeferredGpuCommandService::GetInstance(),
                     shared_renderer_state_->GetSharedContext());
   scoped_ptr<ParentOutputSurface> output_surface_holder(
       new ParentOutputSurface(context_provider));
   output_surface_ = output_surface_holder.get();
   return output_surface_holder.PassAs<cc::OutputSurface>();
 }
 
 void HardwareRenderer::UnusedResourcesAreAvailable() {
   cc::ReturnedResourceArray returned_resources;
   resource_collection_->TakeUnusedResourcesForChildCompositor(
       &returned_resources);
   shared_renderer_state_->InsertReturnedResources(returned_resources);
 }
 
 }  // namespace android_webview