Refactor renderer LayerTreeSettings generating code to common.

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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/gpu/render_widget_compositor.h"
 
 #include <stddef.h>
 #include <limits>
 #include <string>
 #include <utility>
@@ skipping 23 matching lines @@
 #include "cc/output/copy_output_request.h"
 #include "cc/output/copy_output_result.h"
 #include "cc/output/latency_info_swap_promise.h"
 #include "cc/output/swap_promise.h"
 #include "cc/proto/compositor_message.pb.h"
 #include "cc/resources/single_release_callback.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/trees/latency_info_swap_promise_monitor.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/remote_proto_channel.h"
+#include "content/common/compositor_util.h"
 #include "content/common/content_switches_internal.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "content/renderer/gpu/render_widget_compositor_delegate.h"
 #include "content/renderer/input/input_handler_manager.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "third_party/WebKit/public/platform/WebCompositeAndReadbackAsyncCallback.h"
 #include "third_party/WebKit/public/platform/WebCompositorMutatorClient.h"
@@ skipping 283 matching lines @@
   settings.use_partial_raster = compositor_deps->IsPartialRasterEnabled();
   settings.enable_elastic_overscroll =
       compositor_deps->IsElasticOverscrollEnabled();
   settings.renderer_settings.use_gpu_memory_buffer_resources =
       compositor_deps->IsGpuMemoryBufferCompositorResourcesEnabled();
   settings.renderer_settings.buffer_to_texture_target_map =
       compositor_deps->GetBufferToTextureTargetMap();
   settings.image_decode_tasks_enabled =
       compositor_deps->AreImageDecodeTasksEnabled();
 
-  if (cmd.HasSwitch(cc::switches::kTopControlsShowThreshold)) {
-    std::string top_threshold_str =
-        cmd.GetSwitchValueASCII(cc::switches::kTopControlsShowThreshold);
-    double show_threshold;
-    if (base::StringToDouble(top_threshold_str, &show_threshold) &&
-        show_threshold >= 0.f && show_threshold <= 1.f)
-      settings.top_controls_show_threshold = show_threshold;
-  }
+  // Build LayerTreeSettings from command line args.
+  CompositorUtil::GenerateLayerTreeSettings(settings, cmd);

[Khushal, 2016/08/29 20:21:14]

Do you want to just call it SetTopControlsSettings and move the part below as
well, they belong together. Its nice that we decompose this massive function
into these units now that we're moving it.

Later on you can put all these small functions within the compositor_util.cc
file itself and expose just one GenerateRendererLayerTreeSettings that will call
all of these.

[xingliu, 2016/08/29 20:44:33]

Done.

 
   if (cmd.HasSwitch(cc::switches::kTopControlsHideThreshold)) {
     std::string top_threshold_str =
         cmd.GetSwitchValueASCII(cc::switches::kTopControlsHideThreshold);
     double hide_threshold;
     if (base::StringToDouble(top_threshold_str, &hide_threshold) &&
         hide_threshold >= 0.f && hide_threshold <= 1.f)
       settings.top_controls_hide_threshold = hide_threshold;
   }
 
@@ skipping 787 matching lines @@
 
   remote_proto_channel_receiver_->OnProtoReceived(std::move(deserialized));
 }
 
 void RenderWidgetCompositor::SetPaintedDeviceScaleFactor(
     float device_scale) {
   layer_tree_host_->GetLayerTree()->SetPaintedDeviceScaleFactor(device_scale);
 }
 
 }  // namespace content