This is in the gallery app in a B2G build with bug 768901 fixed. See bug 811021 comment 0 for instructions about getting photos into the gallery app on desktop-Linux-B2G. ==16799== Double report of heap block 0x18FB9960: ==16799== Allocated ==16799== at 0x402B4A1: realloc (vg_replace_malloc.c:662) ==16799== by 0x603D9AB: nsVoidArray::SizeTo(int) (nsVoidArray.cpp:166) ==16799== by 0x603DB4C: nsVoidArray::GrowArrayBy(int) (nsVoidArray.cpp:263) ==16799== by 0x603DE17: nsVoidArray::InsertElementAt(void*, int) (nsVoidArray.cpp:425) ==16799== by 0x603AC9E: nsCOMArray_base::InsertObjectAt(nsISupports*, int) (nsCOMArray.cpp:49) ==16799== by 0x51C48FE: nsCOMArray_base::AppendObject(nsISupports*) (nsCOMArray.h:53) ==16799== by 0x54ECA05: nsCOMArray<mozilla::css::Rule>::AppendObject(mozilla::css::Rule*) (nsCOMArray.h:229) ==16799== by 0x5501CFC: nsCSSStyleSheet::AppendStyleRule(mozilla::css::Rule*) (nsCSSStyleSheet.cpp:1470) ==16799== Previously reported by 'windows' ==16799== at 0x58BE36E: DOMStyleMallocSizeOf(void const*) (nsWindowMemoryReporter.cpp:108) ==16799== by 0x603E1F5: nsVoidArray::SizeOfExcludingThis(unsigned long (*)(void const*, unsigned long (*)(void const*), void*), unsigned long (*)(void const*), void*) const (nsVoidArray.cpp:749) ==16799== by 0x550092F: nsCSSStyleSheetInner::SizeOfIncludingThis(unsigned long (*)(void const*)) const (nsCSSStyleSheet.cpp:1006) ==16799== by 0x550089A: nsCSSStyleSheet::SizeOfIncludingThis(unsigned long (*)(void const*)) const (nsCSSStyleSheet.cpp:874) ==16799== by 0x603E24E: SizeOfElementIncludingThisEnumerator(void const*, void*) (nsVoidArray.cpp:737) ==16799== by 0x603E14E: nsVoidArray::EnumerateForwards(bool (*)(void const*, void*), void*) const (nsVoidArray.cpp:704) ==16799== by 0x603E227: nsVoidArray::SizeOfExcludingThis(unsigned long (*)(void const*, unsigned long (*)(void const*), void*), unsigned long (*)(void const*), void*) const (nsVoidArray.cpp:755) ==16799== by 0x5603391: nsDocument::DocSizeOfExcludingThis(nsWindowSizes*) const (nsDocument.cpp:9648) ==16799== Now reported by 'windows' ==16799== at 0x58BE36E: DOMStyleMallocSizeOf(void const*) (nsWindowMemoryReporter.cpp:108) ==16799== by 0x603E1F5: nsVoidArray::SizeOfExcludingThis(unsigned long (*)(void const*, unsigned long (*)(void const*), void*), unsigned long (*)(void const*), void*) const (nsVoidArray.cpp:749) ==16799== by 0x550092F: nsCSSStyleSheetInner::SizeOfIncludingThis(unsigned long (*)(void const*)) const (nsCSSStyleSheet.cpp:1006) ==16799== by 0x550089A: nsCSSStyleSheet::SizeOfIncludingThis(unsigned long (*)(void const*)) const (nsCSSStyleSheet.cpp:874) ==16799== by 0x603F934: SizeOfEntryExcludingThisEnumerator(PLDHashTable*, PLDHashEntryHdr*, unsigned int, void*) (pldhash.cpp:773) ==16799== by 0x603F80F: PL_DHashTableEnumerate (pldhash.cpp:717) ==16799== by 0x603F901: PL_DHashTableSizeOfExcludingThis (pldhash.cpp:787) ==16799== by 0x54D8838: nsBaseHashtable<mozilla::URIPrincipalAndCORSModeHashKey, nsRefPtr<nsCSSStyleSheet>, nsCSSStyleSheet*>::SizeOfExcludingThis(unsigned long (*)(mozilla::URIPrincipalAndCORSModeHashKey*, nsRefPtr<nsCSSStyleSheet> const&, unsigned long (*)(void const*), void*), unsigned long (*)(void const*), void*) const (nsBaseHashtable.h:288)

Actually...looking through the DMD log, this is probably a dupe of bug 811021. There are a lot of double-reported CSS fields.