Expose a low-end device mode override flags for non-android OSs as well

content/renderer/render_widget.cc

 // Copyright (c) 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 "content/renderer/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_synthetic_delay.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/sys_utils.h"
 #include "build/build_config.h"
 #include "cc/base/switches.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/output/output_surface.h"
 #include "cc/trees/layer_tree_host.h"
 #include "content/child/npapi/webplugin.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 #include "content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h"
 #include "content/common/gpu/gpu_process_launch_causes.h"
 #include "content/common/input/synthetic_gesture_packet.h"
@@ skipping 33 matching lines @@
 #include "ui/base/ui_base_switches.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gl/gl_switches.h"
 #include "ui/surface/transport_dib.h"
 #include "webkit/renderer/compositor_bindings/web_rendering_stats_impl.h"
 
 #if defined(OS_ANDROID)
-#include "base/android/sys_utils.h"
 #include "content/renderer/android/synchronous_compositor_factory.h"
 #endif
 
 #if defined(OS_POSIX)
 #include "ipc/ipc_channel_posix.h"
 #include "third_party/skia/include/core/SkMallocPixelRef.h"
 #include "third_party/skia/include/core/SkPixelRef.h"
 #endif  // defined(OS_POSIX)
 
 #include "third_party/WebKit/public/web/WebWidget.h"
@@ skipping 849 matching lines @@
     return scoped_ptr<cc::OutputSurface>(
         new DelegatedCompositorOutputSurface(
             routing_id(),
             output_surface_id,
             context_provider,
             scoped_ptr<cc::SoftwareOutputDevice>()));
   }
   if (command_line.HasSwitch(cc::switches::kCompositeToMailbox)) {
     DCHECK(is_threaded_compositing_enabled_);
     cc::ResourceFormat format = cc::RGBA_8888;
-#if defined(OS_ANDROID)
-    if (base::android::SysUtils::IsLowEndDevice())
+    if (base::SysUtils::IsLowEndDevice())
       format = cc::RGB_565;
-#endif
     return scoped_ptr<cc::OutputSurface>(
         new MailboxOutputSurface(
             routing_id(),
             output_surface_id,
             context_provider,
             scoped_ptr<cc::SoftwareOutputDevice>(),
             format));
   }
   bool use_swap_compositor_frame_message = false;
   return scoped_ptr<cc::OutputSurface>(
@@ skipping 1883 matching lines @@
   if (!RenderThreadImpl::current())
     return scoped_ptr<WebGraphicsContext3DCommandBufferImpl>();
   CauseForGpuLaunch cause =
       CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE;
   scoped_refptr<GpuChannelHost> gpu_channel_host(
       RenderThreadImpl::current()->EstablishGpuChannelSync(cause));
   if (!gpu_channel_host)
     return scoped_ptr<WebGraphicsContext3DCommandBufferImpl>();
 
   WebGraphicsContext3DCommandBufferImpl::SharedMemoryLimits limits;
-#if defined(OS_ANDROID)
   // If we raster too fast we become upload bound, and pending
   // uploads consume memory. For maximum upload throughput, we would
   // want to allow for upload_throughput * pipeline_time of pending
   // uploads, after which we are just wasting memory. Since we don't
   // know our upload throughput yet, this just caps our memory usage.
-  size_t divider = 1;
-  if (base::android::SysUtils::IsLowEndDevice())
-    divider = 6;
+
   // For reference Nexus10 can upload 1MB in about 2.5ms.
-  const double max_mb_uploaded_per_ms = 2.0 / (5 * divider);
+  const double max_mb_uploaded_per_ms = 2.0 / 5;
   // Deadline to draw a frame to achieve 60 frames per second.
   const size_t kMillisecondsPerFrame = 16;
   // Assuming a two frame deep pipeline between the CPU and the GPU.
-  size_t max_transfer_buffer_usage_mb =
+  const size_t max_transfer_buffer_usage_mb =
       static_cast<size_t>(2 * kMillisecondsPerFrame * max_mb_uploaded_per_ms);
   static const size_t kBytesPerMegabyte = 1024 * 1024;
   // We keep the MappedMemoryReclaimLimit the same as the upload limit
   // to avoid unnecessarily stalling the compositor thread.
-  limits.mapped_memory_reclaim_limit =
-      max_transfer_buffer_usage_mb * kBytesPerMegabyte;
+  if (base::SysUtils::IsLowEndDevice())

[piman, 2014/01/21 21:23:49]

needs braces

+    limits.mapped_memory_reclaim_limit =
+        max_transfer_buffer_usage_mb / 6 * kBytesPerMegabyte;
+#if defined(OS_ANDROID)
+  else
+    limits.mapped_memory_reclaim_limit =
+        max_transfer_buffer_usage_mb * kBytesPerMegabyte;
 #endif
 
   scoped_ptr<WebGraphicsContext3DCommandBufferImpl> context(
       new WebGraphicsContext3DCommandBufferImpl(
           surface_id(),
           GetURLForGraphicsContext3D(),
           gpu_channel_host.get(),
           attributes,
           false /* bind generates resources */,
           limits));
   return context.Pass();
 }
 
 }  // namespace content