GPU process clients can perform a "shallow" finish.

cc/output/software_renderer.cc

 // Copyright 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 "cc/output/software_renderer.h"
 
 #include "base/debug/trace_event.h"
 #include "cc/base/math_util.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
@@ skipping 110 matching lines @@
 void SoftwareRenderer::EnsureScissorTestDisabled() {
   // There is no explicit notion of enabling/disabling scissoring in software
   // rendering, but the underlying effect we want is to clear any existing
   // clipRect on the current SkCanvas. This is done by setting clipRect to
   // the viewport's dimensions.
   is_scissor_enabled_ = false;
   SkDevice* device = current_canvas_->getDevice();
   SetClipRect(gfx::Rect(device->width(), device->height()));
 }
 
-void SoftwareRenderer::Finish() {}
+//void SoftwareRenderer::Finish() {}
 
 void SoftwareRenderer::BindFramebufferToOutputSurface(DrawingFrame* frame) {
   current_framebuffer_lock_.reset();
   current_canvas_ = root_canvas_;
 }
 
 bool SoftwareRenderer::BindFramebufferToTexture(
     DrawingFrame* frame,
     const ScopedResource* texture,
     gfx::Rect target_rect) {
@@ skipping 330 matching lines @@
                              4 * rect.width());
 }
 
 void SoftwareRenderer::SetVisible(bool visible) {
   if (visible_ == visible)
     return;
   visible_ = visible;
 }
 
 }  // namespace cc