Add --disable-low-res-tiling. Disable low res tiling to save power.

cc/base/switches.cc

Index: cc/base/switches.cc
diff --git a/cc/base/switches.cc b/cc/base/switches.cc
index 46f4992dd2ac4c73d598bd032a250ad55b8ae57a..108795d00211ac64cb6736886824c4b4342c8bad 100644
--- a/cc/base/switches.cc
+++ b/cc/base/switches.cc
@@ -18,6 +18,15 @@ const char kDisableCompositedAntialiasing[] =
 const char kEnableTopControlsPositionCalculation[] =
     "enable-top-controls-position-calculation";
 
+// When using CPU rasterizing generate low resolution tiling. Low res
+// tiles may be displayed during fast scrolls especially on slower devices.
+const char kEnableLowResTiling[] = "enable-low-res-tiling";
+
+// When using CPU rasterizing disable low resolution tiling. This uses
+// less power, particularly during animations, but more white may be seen
+// during fast scrolling especially on slower devices.
+const char kDisableLowResTiling[] = "disable-low-res-tiling";
+
 // The height of the movable top controls.
 const char kTopControlsHeight[] = "top-controls-height";
 
@@ -114,5 +123,16 @@ const char kCCRebaselinePixeltests[] = "cc-rebaseline-pixeltests";
 const char kDisableCompositorTouchHitTesting[] =
     "disable-compositor-touch-hit-testing";
 
+bool IsLowResTilingEnabled() {

[piman, 2014/03/13 00:52:00]

Nit: this is only used in the renderer. Could this be a bool on
RenderThreadImpl, similar to other related state? Like e.g.
RenderThreadImpl::is_impl_side_painting_enabled()
That way we don't have to parse strings every time we create a compositor. Also
maybe one day we won't have to pass a gigantic command line to the renderer.

+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+
+  if (command_line.HasSwitch(switches::kDisableLowResTiling))
+    return false;
+  else if (command_line.HasSwitch(switches::kEnableLowResTiling))
+    return true;
+
+  return true;
+}
+
 }  // namespace switches
 }  // namespace cc