cc: Increase kMaxCopyOperations to 32.

Increase max number of copy operations from 16 to 32. This
improves the throughput on systems where raster performance
is relatively high.

BUG=454898

Review URL: https://codereview.chromium.org/937843006

Cr-Commit-Position: refs/heads/master@{#317614}

cc/resources/one_copy_tile_task_worker_pool.cc

@@ -78,7 +78,7 @@ class RasterBufferImpl : public RasterBuffer {
 const int kCopyFlushPeriod = 4;
 
 // Number of in-flight copy operations to allow.
-const int kMaxCopyOperations = 16;
+const int kMaxCopyOperations = 32;
 
 // Delay been checking for copy operations to complete.
 const int kCheckForCompletedCopyOperationsTickRateMs = 1;