add gm to show miplevels

add gm to show miplevels

BUG=skia:
TBR=

NOTREECHECKS=true

Committed: https://skia.googlesource.com/skia/+/a598f4b773f066a939e0216a116c179b90550727

[reed1, 2015-01-15 22:07:44]

The CQ bit was checked by reed@google.com

[commit-bot: I haz the power, 2015-01-15 22:08:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/849173004/1

[commit-bot: I haz the power, 2015-01-15 22:08:26]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-01-16 04:08 UTC

[commit-bot: I haz the power, 2015-01-15 22:09:55]

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

[commit-bot: I haz the power, 2015-01-15 22:09:56]

Try jobs failed on following builders:
  Test-Ubuntu13.10-GCE-NoGPU-x86_64-Release-Shared-Trybot on client.skia
(http://build.chromium.org/p/client.skia/builders/Test-Ubuntu13.10-GCE-NoGPU-x...)
  Build-Ubuntu13.10-GCC4.8-x86_64-Release-Trybot on client.skia.compile
(http://build.chromium.org/p/client.skia.compile/builders/Build-Ubuntu13.10-GC...)

[reed1, 2015-01-15 22:10:49]

The CQ bit was checked by reed@google.com

[commit-bot: I haz the power, 2015-01-15 22:11:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/849173004/20001

[commit-bot: I haz the power, 2015-01-15 22:11:26]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-01-16 04:11 UTC

[reed1, 2015-01-15 22:20:02]

The CQ bit was unchecked by reed@google.com

[reed1, 2015-01-15 22:20:09]

The CQ bit was checked by reed@google.com

[commit-bot: I haz the power, 2015-01-15 22:20:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/849173004/20001

[mtklein, 2015-01-16 02:08:58]

The CQ bit was unchecked by mtklein@google.com

[mtklein, 2015-01-16 02:09:03]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2015-01-16 02:09:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/849173004/20001

[commit-bot: I haz the power, 2015-01-16 02:09:21]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/a598f4b773f066a939e0216a116c179b90550727

[mtklein, 2015-01-16 02:34:55]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/854103004/ by mtklein@google.com.

The reason for reverting is: ==31530==ERROR: LeakSanitizer: detected memory
leaks

Direct leak of 224 byte(s) in 2 object(s) allocated from:
    #0 0x7febb223f65b in operator new(unsigned long)
(/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/dm+0x35865b)
    #1 0x7febb3483c56 in SkMipMap::Build(SkBitmap const&, SkDiscardableMemory*
(*)(unsigned long))
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../src/core/SkMipMap.cpp:181:9
    #2 0x7febb2c37914 in ShowMipLevels::onDraw(SkCanvas*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../gm/downsamplebitmap.cpp:228:24
    #3 0x7febb2295736 in skiagm::GM::drawContent(SkCanvas*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../gm/gm.cpp:32:5
    #4 0x7febb2295019 in skiagm::GM::draw(SkCanvas*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../gm/gm.cpp:24:5
    #5 0x7febb226722f in DM::GMSrc::draw(SkCanvas*) const
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../dm/DMSrcSink.cpp:22:5
    #6 0x7febb226d929 in DM::RasterSink::draw(DM::Src const&, SkBitmap*,
SkWStream*) const
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../dm/DMSrcSink.cpp:230:12
    #7 0x7febb224e004 in Task::Run(Task*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../dm/DM.cpp:254:25
    #8 0x7febb3805e4c in (anonymous namespace)::ThreadPool::Loop(void*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../src/core/SkTaskGroup.cpp:149:13
    #9 0x7febb460dc7c in thread_start(void*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../src/utils/SkThreadUtils_pthread.cpp:66:9
    #10 0x7febb1251f6d in start_thread
/build/buildd/eglibc-2.17/nptl/pthread_create.c:311

Indirect leak of 699528 byte(s) in 2 object(s) allocated from:
    #0 0x7febb22214ab in __interceptor_malloc
(/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/dm+0x33a4ab)
    #1 0x7febb473e3c6 in sk_malloc_flags(unsigned long, unsigned int)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../src/ports/SkMemory_malloc.cpp:54:15
    #2 0x7febb473e19a in sk_malloc_throw(unsigned long)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../src/ports/SkMemory_malloc.cpp:40:12
    #3 0x7febb3483c94 in SkMipMap::Build(SkBitmap const&, SkDiscardableMemory*
(*)(unsigned long))
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../src/core/SkMipMap.cpp:181:18
    #4 0x7febb2c37914 in ShowMipLevels::onDraw(SkCanvas*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../gm/downsamplebitmap.cpp:228:24
    #5 0x7febb2295736 in skiagm::GM::drawContent(SkCanvas*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../gm/gm.cpp:32:5
    #6 0x7febb2295019 in skiagm::GM::draw(SkCanvas*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../gm/gm.cpp:24:5
    #7 0x7febb226722f in DM::GMSrc::draw(SkCanvas*) const
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../dm/DMSrcSink.cpp:22:5
    #8 0x7febb226d929 in DM::RasterSink::draw(DM::Src const&, SkBitmap*,
SkWStream*) const
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../dm/DMSrcSink.cpp:230:12
    #9 0x7febb224e004 in Task::Run(Task*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../dm/DM.cpp:254:25
    #10 0x7febb3805e4c in (anonymous namespace)::ThreadPool::Loop(void*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../src/core/SkTaskGroup.cpp:149:13
    #11 0x7febb460dc7c in thread_start(void*)
/home/default/storage/skia-repo/buildbot/skiabot-linux-xsan-001/build/slave/Test-Ubuntu13_10-GCE-NoGPU-x86_64-Debug-ASAN/build/skia/out/Debug/../../src/utils/SkThreadUtils_pthread.cpp:66:9
    #12 0x7febb1251f6d in start_thread
/build/buildd/eglibc-2.17/nptl/pthread_create.c:311
.