Fix Tricium error

There is a C-style cast in gpu_raster_buffer_provider.cc which Tricium
would prefer to be a C++-style cast.

This CL changes it that cast.

Change-Id: If4fe2d1d39153431a71f60f866ab928154d729d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2354049Reviewed-by: vmpstr <vmpstr@chromium.org>
Commit-Queue: Chris Blume <cblume@chromium.org>
Auto-Submit: Chris Blume <cblume@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797805}

cc/raster/gpu_raster_buffer_provider.cc

@@ -378,7 +378,7 @@ GpuRasterBufferProvider::GpuRasterBufferProvider(
       unpremultiply_and_dither_low_bit_depth_tiles_(
           unpremultiply_and_dither_low_bit_depth_tiles),
       enable_oop_rasterization_(enable_oop_rasterization),
-      random_generator_((uint32_t)base::RandUint64()),
+      random_generator_(static_cast<uint32_t>(base::RandUint64())),
       bernoulli_distribution_(raster_metric_probability) {
   DCHECK(compositor_context_provider);
   DCHECK(worker_context_provider);