cc: Implement deadine scheduling disabled by default

cc/base/switches.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 "cc/base/switches.h"
 
 #include "base/command_line.h"
 
 namespace cc {
 namespace switches {
 
 // On platforms where checkerboards are used, prefer background colors instead
 // of checkerboards.
 const char kBackgroundColorInsteadOfCheckerboard[] =
     "background-color-instead-of-checkerboard";
 
 const char kDisableThreadedAnimation[] = "disable-threaded-animation";
 
 // Disables layer-edge anti-aliasing in the compositor.
 const char kDisableCompositedAntialiasing[] =
     "disable-composited-antialiasing";
 
 // Paint content on the main thread instead of the compositor thread.
 // Overrides the kEnableImplSidePainting flag.
 const char kDisableImplSidePainting[] = "disable-impl-side-painting";
 
 // Paint content on the compositor thread instead of the main thread.
 const char kEnableImplSidePainting[] = "enable-impl-side-painting";
 
+// Disables the deadline scheduler.
+// Overrides the kDisableDeadlineScheduling flag.

[enne (OOO), 2013/09/10 03:35:44]

typo? s/Disable/Enable/

[brianderson, 2013/09/10 21:16:56]

Done.

+const char kDisableDeadlineScheduling[] = "disable-deadline-scheduling";
+
+// Deadline scheduling gives children compositors and the main thread an
+// interval over which they can produce content instead of always consuming
+// their input on the next BeginFrame. This allows a total pipeline latency
+// of less than 1 vsync if their intervals are properly nested.
+const char kEnableDeadlineScheduling[] = "enable-deadline-scheduling";
+
 const char kEnableTopControlsPositionCalculation[] =
     "enable-top-controls-position-calculation";
 
 // For any layers that can get drawn directly to screen, draw them with the Skia
 // GPU backend.  Only valid with gl rendering + threaded compositing + impl-side
 // painting.
 const char kForceDirectLayerDrawing[] = "force-direct-layer-drawing";
 
 // The height of the movable top controls.
 const char kTopControlsHeight[] = "top-controls-height";
@@ skipping 114 matching lines @@
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
   if (command_line.HasSwitch(cc::switches::kDisableMapImage))
     return false;
   else if (command_line.HasSwitch(cc::switches::kEnableMapImage))
     return true;
 
   return false;
 }
 
+bool IsDeadlineSchedulingEnabled() {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+
+  if (command_line.HasSwitch(cc::switches::kDisableDeadlineScheduling))
+    return false;
+  else if (command_line.HasSwitch(cc::switches::kEnableDeadlineScheduling))
+    return true;
+
+#if defined(OS_ANDROID)
+  return true;
+#else
+  return false;
+#endif
+}
+
 }  // namespace switches
 }  // namespace cc