Adding command line switch --gpu-swap-delay to artificially slow down the

GPU process to simulate slow GPUs.

BUG=120469
TEST=None
Review URL: https://chromiumcodereview.appspot.com/9866053

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@129673 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 21 insertions, 0 deletions

diff --git a/ui/gfx/gl/gl_switches.cc b/ui/gfx/gl/gl_switches.cc
index 38828f3..4614989 100644
--- a/ui/gfx/gl/gl_switches.cc
+++ b/ui/gfx/gl/gl_switches.cc
@@ -39,6 +39,10 @@ const char kSwiftShaderPath[]               = "swiftshader-path";
 // context will never be lost in any situations, say, a GPU reset.
 const char kGpuNoContextLost[]              = "gpu-no-context-lost";
 
+// Add a delay in milliseconds to the gpu swap buffer completion signal.
+// Simulates a slow GPU.
+const char kGpuSwapDelay[]                  = "gpu-swap-delay";
+
 // Flag used for Linux tests: for desktop GL bindings, try to load this GL
 // library first, but fall back to regular library if loading fails.
 const char kTestGLLib[]                     = "test-gl-lib";
diff --git a/ui/gfx/gl/gl_switches.h b/ui/gfx/gl/gl_switches.h
index 6f4460e..7dc2dc8b 100644
--- a/ui/gfx/gl/gl_switches.h
+++ b/ui/gfx/gl/gl_switches.h
@@ -28,6 +28,7 @@ GL_EXPORT extern const char kDisableGpuVsync[];
 GL_EXPORT extern const char kEnableGPUServiceLogging[];
 GL_EXPORT extern const char kEnableGPUClientLogging[];
 GL_EXPORT extern const char kGpuNoContextLost[];
+GL_EXPORT extern const char kGpuSwapDelay[];
 GL_EXPORT extern const char kUseGL[];
 GL_EXPORT extern const char kSwiftShaderPath[];
 GL_EXPORT extern const char kTestGLLib[];
diff --git a/ui/gfx/surface/accelerated_surface_win.cc b/ui/gfx/surface/accelerated_surface_win.cc
index f2a05bd..c1f0c66 100644
--- a/ui/gfx/surface/accelerated_surface_win.cc
+++ b/ui/gfx/surface/accelerated_surface_win.cc
@@ -11,6 +11,8 @@
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/command_line.h"
+#include "base/string_number_conversions.h"
+#include "base/time.h"
 #include "base/debug/trace_event.h"
 #include "base/file_path.h"
 #include "base/lazy_instance.h"
@@ -476,6 +478,16 @@ void AcceleratedPresenter::Invalidate() {
 AcceleratedPresenter::~AcceleratedPresenter() {
 }
 
+static base::TimeDelta GetSwapDelay() {
+  CommandLine* cmd_line = CommandLine::ForCurrentProcess();
+  int delay = 0;
+  if (cmd_line->HasSwitch(switches::kGpuSwapDelay)) {
+    base::StringToInt(cmd_line->GetSwitchValueNative(
+        switches::kGpuSwapDelay).c_str(), &delay);
+  }
+  return base::TimeDelta::FromMilliseconds(delay);
+}
+
 void AcceleratedPresenter::DoPresentAndAcknowledge(
     const gfx::Size& size,
     int64 surface_handle,
@@ -609,6 +621,10 @@ void AcceleratedPresenter::DoPresentAndAcknowledge(
     } while (hr == S_FALSE);
   }
 
+  static const base::TimeDelta swap_delay = GetSwapDelay();
+  if (swap_delay.ToInternalValue())
+    base::PlatformThread::Sleep(swap_delay);
+
   scoped_completion_runner.Release();
   if (!completion_task.is_null())
     completion_task.Run(true);