Revert of Remove --enable-per-tile-painting and --ui-enable-per-tile-painting.

cc/base/switches.cc

Index: cc/base/switches.cc
diff --git a/cc/base/switches.cc b/cc/base/switches.cc
index 7820420db2866a943ea4c9b44321110db8198e72..7e45074030db420352e32bc3aeea30964b39b51c 100644
--- a/cc/base/switches.cc
+++ b/cc/base/switches.cc
@@ -85,6 +85,9 @@
 const char kEnablePartialSwap[] = "enable-partial-swap";
 // Disable partial swap which is needed for some OpenGL drivers / emulators.
 const char kUIDisablePartialSwap[] = "ui-disable-partial-swap";
+
+const char kEnablePerTilePainting[] = "enable-per-tile-painting";
+const char kUIEnablePerTilePainting[] = "ui-enable-per-tile-painting";
 
 // Enables the GPU benchmarking extension
 const char kEnableGpuBenchmarking[] = "enable-gpu-benchmarking";