Fix C4334 warning about 32-bit shift assigned to 64-bits

VS 2015 has a new or louder warning about 32-bit shifts that are then
assigned to a 64-bit target. This type of code triggers it:

int64_t size = 1 << shift_amount;

Because the '1' being shifted is a 32-bit int the result of the shift
will be a 32-bit result, so assigning it to a 64-bit variable is just
misleading.

In this case the code that triggers it is this:

  size_t alloc = 1<<fLgSize++;

The destination is a size_t so the warning only shows up on 64-bit
builds and doesn't indicate a real bug. But, casting the '1' constant
to size_t makes the behavior/intent more obvious and consistent and
allows enabling C4334 in Chromium.

BUG=593448
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1845123002

Review URL: https://codereview.chromium.org/1845123002

0 files changed, 0 insertions, 0 deletions