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

1 files changed, 1 insertions, 1 deletions

diff --git a/src/core/SkVarAlloc.cpp b/src/core/SkVarAlloc.cpp
index 1fbd382c19..ea0524b67f 100644
--- a/src/core/SkVarAlloc.cpp
+++ b/src/core/SkVarAlloc.cpp
@@ -45,7 +45,7 @@ SkVarAlloc::~SkVarAlloc() {
 void SkVarAlloc::makeSpace(size_t bytes) {
     SkASSERT(SkIsAlignPtr(bytes));
 
-    size_t alloc = 1<<fLgSize++;
+    size_t alloc = static_cast<size_t>(1)<<fLgSize++;
     while (alloc < bytes + sizeof(Block)) {
         alloc *= 2;
     }