For non-opaque SkBitmapDevices, replace malloc-then-zero with calloc.

For non-opaque SkBitmapDevices, replace malloc-then-zero with calloc.

There seem about a zillion possible ways to slice this.
This adds and uses SkMallocPixelRef::ZeroedPRFactory.
I'm not married to it.

This appears to clear up a hot spot in the benchmark referenced in this bug:
BUG=516426
I'm not confident enough on Windows to declare that definitively yet.

It probably helps all other non-opaque layers too.  Possibly significantly.

So I don't forget, I profiled this:
out/Release/performance_browser_tests.exe  --gtest_filter=TabCapturePerformanceTest.Performance/2 --single-process

No diffs:
https://gold.skia.org/search2?issue=1430593007&unt=true&query=source_type%3Dgm&master=false

TBR=reed@google.com

Committed: https://skia.googlesource.com/skia/+/cd4954152490c7492284a7914571531ba8c75b4a

[mtklein_C, 2015-11-04 20:11:08]

Description was changed from

==========
For non-opaque SkBitmapDevices, replace malloc-then-zero with calloc.

There seem about a zillion possible ways to slice this.
This adds and uses SkMallocPixelRef::ZeroedPRFactory.
I'm not married to it.

This clears up a hot spot in the benchmark referenced in this bug:
BUG=516426

So I don't forget, profiled:
out/Release/performance_browser_tests.exe 
--gtest_filter=TabCapturePerformanceTest.Performance/2 --single-process
==========

to

==========
For non-opaque SkBitmapDevices, replace malloc-then-zero with calloc.

There seem about a zillion possible ways to slice this.
This adds and uses SkMallocPixelRef::ZeroedPRFactory.
I'm not married to it.

This appears to clear up a hot spot in the benchmark referenced in this bug:
BUG=516426
I'm not confident enough on Windows to declare that definitively yet.

It probably helps all other non-opaque layers too.  Possibly significantly.

So I don't forget, I profiled this:
out/Release/performance_browser_tests.exe 
--gtest_filter=TabCapturePerformanceTest.Performance/2 --single-process
==========

[mtklein_C, 2015-11-04 20:13:12]

The CQ bit was checked by mtklein@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-11-04 20:13:21]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1430593007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1430593007/1

[mtklein_C, 2015-11-04 20:23:51]

mtklein@chromium.org changed reviewers:
+ reed@google.com

[commit-bot: I haz the power, 2015-11-04 20:24:15]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-11-04 20:24:15]

Dry run: This issue passed the CQ dry run.

[mtklein_C, 2015-11-04 20:44:28]

Description was changed from

==========
For non-opaque SkBitmapDevices, replace malloc-then-zero with calloc.

There seem about a zillion possible ways to slice this.
This adds and uses SkMallocPixelRef::ZeroedPRFactory.
I'm not married to it.

This appears to clear up a hot spot in the benchmark referenced in this bug:
BUG=516426
I'm not confident enough on Windows to declare that definitively yet.

It probably helps all other non-opaque layers too.  Possibly significantly.

So I don't forget, I profiled this:
out/Release/performance_browser_tests.exe 
--gtest_filter=TabCapturePerformanceTest.Performance/2 --single-process
==========

to

==========
For non-opaque SkBitmapDevices, replace malloc-then-zero with calloc.

There seem about a zillion possible ways to slice this.
This adds and uses SkMallocPixelRef::ZeroedPRFactory.
I'm not married to it.

This appears to clear up a hot spot in the benchmark referenced in this bug:
BUG=516426
I'm not confident enough on Windows to declare that definitively yet.

It probably helps all other non-opaque layers too.  Possibly significantly.

So I don't forget, I profiled this:
out/Release/performance_browser_tests.exe 
--gtest_filter=TabCapturePerformanceTest.Performance/2 --single-process

No diffs:
https://gold.skia.org/search2?issue=1430593007&unt=true&query=source_type%3Dg...
==========

[mtklein, 2015-11-05 16:33:00]

The CQ bit was checked by mtklein@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-11-05 16:33:13]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1430593007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1430593007/1

[commit-bot: I haz the power, 2015-11-05 16:33:55]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-11-05 16:33:56]

Dry run: This issue passed the CQ dry run.

[mtklein, 2015-11-05 17:45:40]

Description was changed from

==========
For non-opaque SkBitmapDevices, replace malloc-then-zero with calloc.

There seem about a zillion possible ways to slice this.
This adds and uses SkMallocPixelRef::ZeroedPRFactory.
I'm not married to it.

This appears to clear up a hot spot in the benchmark referenced in this bug:
BUG=516426
I'm not confident enough on Windows to declare that definitively yet.

It probably helps all other non-opaque layers too.  Possibly significantly.

So I don't forget, I profiled this:
out/Release/performance_browser_tests.exe 
--gtest_filter=TabCapturePerformanceTest.Performance/2 --single-process

No diffs:
https://gold.skia.org/search2?issue=1430593007&unt=true&query=source_type%3Dg...
==========

to

==========
For non-opaque SkBitmapDevices, replace malloc-then-zero with calloc.

There seem about a zillion possible ways to slice this.
This adds and uses SkMallocPixelRef::ZeroedPRFactory.
I'm not married to it.

This appears to clear up a hot spot in the benchmark referenced in this bug:
BUG=516426
I'm not confident enough on Windows to declare that definitively yet.

It probably helps all other non-opaque layers too.  Possibly significantly.

So I don't forget, I profiled this:
out/Release/performance_browser_tests.exe 
--gtest_filter=TabCapturePerformanceTest.Performance/2 --single-process

No diffs:
https://gold.skia.org/search2?issue=1430593007&unt=true&query=source_type%3Dg...

TBR=reed@google.com
==========

[mtklein, 2015-11-05 17:45:42]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2015-11-05 17:45:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1430593007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1430593007/1

[commit-bot: I haz the power, 2015-11-05 17:46:27]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/cd4954152490c7492284a7914571531ba8c75b4a