Allow one-copy task tile worker pool to use compressed textures.

cc/base/switches.cc

Index: cc/base/switches.cc
diff --git a/cc/base/switches.cc b/cc/base/switches.cc
index 13a9735bff7f42e2b5b8fee170fdc1b0d494eaf7..bf39a7ab87e25755ccc215d8d4c86ff2adedab09 100644
--- a/cc/base/switches.cc
+++ b/cc/base/switches.cc
@@ -50,6 +50,9 @@ const char kStrictLayerPropertyChangeChecking[] =
 const char kEnablePropertyTreeVerification[] =
     "enable-property-tree-verification";
 
+// Compress tile textures for GPUs supporting it.
+const char kEnableTileCompression[] = "enable-tile-compression";
+
 // Use a BeginFrame signal from browser to renderer to schedule rendering.
 const char kEnableBeginFrameScheduling[] = "enable-begin-frame-scheduling";