Oilpan: Fix Resource-related unit test crashes in CachingCorrectnessTest, MemoryCacheTest, and ImageBitmapTest.

MemoryCache::m_liveResources is the main owner of Resource objects. If we
replace the global memory cache and the global memory cache is collected,
Resource objects are also collected unexpectedly even though their canDelete()
is false. So, replaceMemoryCacheForTesting should transfer m_liveResources of
the previous MemoryCache to the new one.

This CL also fixes additional problems.

* MemoryCacheTest.VeryLargeResourceAccounting
* MemoryCacheTest.DecodeCacheOrder
* ImageBitmapTest.ImageBitmapLiveResourcePriority
  Fix Resource leak. We need to unregister ResourceClient manually.

* RawResourceTest.DontIgnoreAcceptForCacheReuse
  Do not allocate garbage-collected object on stack.

BUG=393516

Review URL: https://codereview.chromium.org/426183003

git-svn-id: svn://svn.chromium.org/blink/trunk@179364 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Cleanup: Also simplify wtf_unittests target.

It is seems redundant to have a separate target only for the main() entry.

It looks cleaner to have everything contained into a single target imo.

Previous patch did it for blink_heap_unittests and
blink_platform_unittests in
https://src.chromium.org/viewvc/blink?revision=179353&view=revision

BUG=None
TEST=wtf_unittests
R=tkent@chromium.org

Review URL: https://codereview.chromium.org/436793003

git-svn-id: svn://svn.chromium.org/blink/trunk@179365 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Update a comment so that it contains a bug URL.

BUG=353585
NOTRY=true

Review URL: https://codereview.chromium.org/437593005

git-svn-id: svn://svn.chromium.org/blink/trunk@179366 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix crash in blink::Internals::numberOfScrollableAreas

The frame can be gone since there could have been a navigation that
removes it, as the testcase demonstrates. So like other methods
in Internals test for it first.

BUG=381066

Review URL: https://codereview.chromium.org/436673003

git-svn-id: svn://svn.chromium.org/blink/trunk@179367 bbb929c8-8fbe-4397-9dbb-9b2b20218538