Bug 1400193 (part 2) - Shrink PLDHashTable. r=froydnj. This patch reduces sizeof(PLDHashTable) as follows. - 64-bit: from 40 bytes to 32 - 32-bit: from 28 bytes to 20 It does this by doing the following. - It moves mGeneration from EntryStore to PLDHashTable, to avoid unnecessary padding on 64-bit. This requires tweaking EntryStore::Set() as explained in a comment. - It also shrinks mGeneration from uint32_t to uint16_t, saving 2 bytes of data. - It shrinks mEntrySize from uint32_t to uint8_t, to cut 3 bytes of data. - It shrinks mHashShift from int16_t to uint8_t, trimming another byte of data, and moves it, saving another 2 bytes of padding. And it reorders the fields so the word-sized ones are at the start, which makes it easier to imagine the memory layout. The patch also adds a test, and fixes some misordered function arguments in existing tests.

Bug 1400193 (part 1) - Fix subtle bug in PLDHashTable's move constructor. r=froydnj. The current code replaces one PLDHashTable's mGeneration with another. If the two generation values happen to be equal, it will look as though the storage hasn't changed when really it has. The fix is to use EntryStore::Set() to update mEntryStore, which increments mGeneration appropriately.

Merge m-c to inbound, a=merge MozReview-Commit-ID: IsEMW5gXG3W

Bug 1400777 (part 5) - Clean up nsElementTable.{cpp,h}. r=mrbkap. This patch makes some style fixes and other minor improvements.

Bug 1400777 (part 4) - Split nsHTMLElement. r=mrbkap. This patch splits out most of nsHTMLElement into a new type HTMLElement within nsElementTable.cpp. Only the static methods IsContainer() and IsBlock() need to remain exposed via nsHTMLElement. The patch moves TestBits() into nsElementTable.cpp as well.

Bug 1400777 (part 3) - De-expose gHTMLElements[]. r=mrbkap.

Bug 1400777 (part 2) - De-expose HTML group constants[]. r=mrbkap. The patch also removes some low-value comments.

Bug 1400777 (part 1) - Remove eHTMLTags. r=mrbkap. It's just a too-cute-by-half typedef for nsHTMLTag.

Bug 1387920 - Drop all ImageContainers' ImageClients during disabling WebRender r=nical

Bug 1386712 - Add null-checking to fix test bustage. r=me

Bug 1400528 - make test_bug574663.html wait until the 'blank' attribute has actually been removed, r=mconley.

Bug 1401100 - Remove nsIMemoryReporterCallback. r=erahm. nsIHandleReportCallback, typedef of nsIMemoryReporterCallback, has been the preferred name for a long time and is used in most places. This patch removes nsIMemoryReporterCallback.

Bug 1386712 - Load about:blank in CustomTabsActivity.finish() to immediately stop media playback. r=snorp

Bug 1401421 - Remove profiler_get_backtrace_noalloc. r=mstange. Bug 1385953 removed MemProfiler, which was its only user.

Bug 1402123 - Disable MediaStream-MediaElement-preload-none.https.html on non-stylo builds a=bustage MozReview-Commit-ID: 6LRGcW4ukVB

Bug 1401524 - Ensure SurfaceCache state coherency whenever we perform an operation that may discard surfaces. r=tnikkel There are a number of operations with the surface cache which may result in individual surfaces for a particular image cache to be removed. If an image cache is emptied, and we are in factor of 2 mode, we should reset it to the default mode, because we require at least one surface to be available to determine the native/ideal size. Additionally, if the cache is not locked, it should be removed entirely from the surface cache. We handle this correctly in methods such as Lookup and LookupBestMatch, but Prune and CollectSizeOfSurfaces can also cause this to happen, as recently done in bug 1370412 and bug 1380649.

Backed out changeset e89d2565799b (bug 1047098) for xpcshell bustage a=backout MozReview-Commit-ID: FRFALkRxDxl

Backed out changeset 04888373f12b (bug 1401878) for xpcshell bustage a=backout MozReview-Commit-ID: AYiI2MJbBbC

Bug 1383501: Obtain and report the current activation context's manifest path; r=jimm MozReview-Commit-ID: HJ1zNoEMzvS

Bug 1369533: Return dead wrappers rather than null for dead CallbackObject values. r=bz We don't have access to an appropriate context to create the dead wrapper in when the callback is nuked, so instead, this patch creates a new dead wrapper in the caller compartment each time the property is accessed. This is the same behavior we'd get when trying to re-wrap a cross-compartment dead wrapper, so it's consistent with the way we handle these situations elsewhere. MozReview-Commit-ID: 3cMeR4z8EOe