cc: Make tiling interest rect calc based on viewport.

cc/base/switches.cc

Index: cc/base/switches.cc
diff --git a/cc/base/switches.cc b/cc/base/switches.cc
index ae424824611ea9fd90d95e94ad238adc6aedcf87..c30ab2fe7f0f91fd83349847444fd481e7372d02 100644
--- a/cc/base/switches.cc
+++ b/cc/base/switches.cc
@@ -35,9 +35,6 @@ const char kTopControlsShowThreshold[] = "top-controls-show-threshold";
 // complete, such as --slow-down-raster-scale-factor=25.
 const char kSlowDownRasterScaleFactor[] = "slow-down-raster-scale-factor";
 
-// Max tiles allowed for each tilings interest area.
-const char kMaxTilesForInterestArea[] = "max-tiles-for-interest-area";
-
 // The amount of unused resource memory compositor is allowed to keep around.
 const char kMaxUnusedResourceMemoryUsagePercentage[] =
     "max-unused-resource-memory-usage-percentage";