cc: Add tile-free software compositing mode.

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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 "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
@@ skipping 584 matching lines @@
     RenderPass::Id target_render_pass_id =
         it.target_render_surface_layer()->render_surface()->RenderPassId();
     RenderPass* target_render_pass =
         frame->render_passes_by_id[target_render_pass_id];
 
     bool prevent_occlusion =
         it.target_render_surface_layer()->HasRequestCopyCallback();
     occlusion_tracker.EnterLayer(it, prevent_occlusion);
 
     AppendQuadsData append_quads_data(target_render_pass->id);
+    if (output_surface_->ForcedDrawToSoftwareDevice())
+      append_quads_data.cannot_append_tile_draw_quads = true;
 
     if (it.represents_target_render_surface()) {
       if (it->HasRequestCopyCallback()) {
         have_copy_request = true;
         it->TakeRequestCopyCallbacks(&target_render_pass->copy_callbacks);
       }
     } else if (it.represents_contributing_render_surface()) {
       RenderPass::Id contributing_render_pass_id =
           it->render_surface()->RenderPassId();
       RenderPass* contributing_render_pass =
@@ skipping 91 matching lines @@
                             active_tree_->background_color(),
                             occlusion_tracker);
   }
 
   if (draw_frame)
     occlusion_tracker.overdraw_metrics()->RecordMetrics(this);
   else
     DCHECK(!have_copy_request);
 
   RemoveRenderPasses(CullRenderPassesWithNoQuads(), frame);
-  renderer_->DecideRenderPassAllocationsForFrame(frame->render_passes);
+  if (!output_surface_->ForcedDrawToSoftwareDevice())
+    renderer_->DecideRenderPassAllocationsForFrame(frame->render_passes);
   RemoveRenderPasses(CullRenderPassesWithCachedTextures(renderer_.get()),
                      frame);
 
   // If we're making a frame to draw, it better have at least one render pass.
   DCHECK(!frame->render_passes.empty());
   return draw_frame;
 }
 
 void LayerTreeHostImpl::UpdateBackgroundAnimateTicking(
     bool should_background_tick) {
@@ skipping 382 matching lines @@
     TRACE_EVENT_INSTANT1("cc.debug", "Frame", TRACE_EVENT_SCOPE_THREAD,
                          "frame", ValueToString(FrameStateAsValue()));
   }
 
   // Because the contents of the HUD depend on everything else in the frame, the
   // contents of its texture are updated as the last thing before the frame is
   // drawn.
   if (active_tree_->hud_layer())
     active_tree_->hud_layer()->UpdateHudTexture(resource_provider_.get());
 
-  renderer_->DrawFrame(&frame->render_passes);
+  if (output_surface_->ForcedDrawToSoftwareDevice()) {
+    scoped_ptr<SoftwareRenderer> temp_software_renderer =
+        SoftwareRenderer::Create(this, output_surface_.get(), NULL);
+    temp_software_renderer->DrawFrame(&frame->render_passes);
+  } else {
+    renderer_->DrawFrame(&frame->render_passes);
+  }
   // The render passes should be consumed by the renderer.
   DCHECK(frame->render_passes.empty());
   frame->render_passes_by_id.clear();
 
   // The next frame should start by assuming nothing has changed, and changes
   // are noted as they occur.
   for (size_t i = 0; i < frame->render_surface_layer_list->size(); i++) {
     (*frame->render_surface_layer_list)[i]->render_surface()->damage_tracker()->
         DidDrawDamagedArea();
   }
@@ skipping 1030 matching lines @@
 }
 
 void LayerTreeHostImpl::SetDebugState(const LayerTreeDebugState& debug_state) {
   if (debug_state_.continuous_painting != debug_state.continuous_painting)
     paint_time_counter_->ClearHistory();
 
   debug_state_ = debug_state;
 }
 
 }  // namespace cc