cc: Handle overflow/underflow in MathUtil::RoundUp/RoundDown functions.

cc/raster/one_copy_tile_task_worker_pool.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/raster/one_copy_tile_task_worker_pool.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/strings/stringprintf.h"
@@ skipping 348 matching lines @@
 
   base::AutoLock lock(lock_);
 
   CopySequenceNumber sequence = 0;
   int bytes_per_row = (BitsPerPixel(raster_resource->format()) *
                        raster_resource->size().width()) /
                       8;
   int chunk_size_in_rows =
       std::max(1, max_bytes_per_copy_operation_ / bytes_per_row);
   // Align chunk size to 4. Required to support compressed texture formats.
-  chunk_size_in_rows = MathUtil::RoundUp(chunk_size_in_rows, 4);
+  chunk_size_in_rows = MathUtil::UncheckedRoundUp(chunk_size_in_rows, 4);
   int y = 0;
   int height = raster_resource->size().height();
   while (y < height) {
     int failed_attempts = 0;
     while ((pending_copy_operations_.size() + issued_copy_operation_count_) >=
            kMaxCopyOperations) {
       // Ignore limit when shutdown is set.
       if (shutdown_)
         break;
 
@@ skipping 201 matching lines @@
       "pending_copy_count",
       static_cast<int>(resource_pool_->total_resource_count() -
                        resource_pool_->acquired_resource_count()));
   staging_state->SetInteger(
       "bytes_pending_copy",
       static_cast<int>(resource_pool_->total_memory_usage_bytes() -
                        resource_pool_->acquired_memory_usage_bytes()));
 }
 
 }  // namespace cc