https://uberchromegw.corp.google.com/i/chromium/builders/Mac/builds/25807 failed the compile and closed the tree.

Interesting bits of the log:

FAILED: test_data/chrome/safe_browsing_dmg/dmg_UDBZ_GPTSPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDBZ_NONE.dmg test_data/chrome/safe_browsing_dmg/dmg_UDBZ_SPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDCO_GPTSPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDCO_NONE.dmg test_data/chrome/safe_browsing_dmg/dmg_UDCO_SPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDRO_GPTSPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDRO_NONE.dmg test_data/chrome/safe_browsing_dmg/dmg_UDRO_SPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDRW_GPTSPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDRW_NONE.dmg test_data/chrome/safe_browsing_dmg/dmg_UDRW_SPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDSP_GPTSPUD.sparseimage test_data/chrome/safe_browsing_dmg/dmg_UDSP_NONE.sparseimage test_data/chrome/safe_browsing_dmg/dmg_UDSP_SPUD.sparseimage test_data/chrome/safe_browsing_dmg/dmg_UDTO_GPTSPUD.cdr test_data/chrome/safe_browsing_dmg/dmg_UDTO_NONE.cdr test_data/chrome/safe_browsing_dmg/dmg_UDTO_SPUD.cdr test_data/chrome/safe_browsing_dmg/dmg_UDZO_GPTSPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UDZO_NONE.dmg test_data/chrome/safe_browsing_dmg/dmg_UDZO_SPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UFBI_GPTSPUD.dmg test_data/chrome/safe_browsing_dmg/dmg_UFBI_NONE.dmg test_data/chrome/safe_browsing_dmg/dmg_UFBI_SPUD.dmg test_data/chrome/safe_browsing_dmg/hfs_plus.img test_data/chrome/safe_browsing_dmg/hfsx_case_sensitive.img test_data/chrome/safe_browsing_dmg/mach_o_in_dmg.dmg 
python ../../build/gn_run_binary.py ../../chrome/test/data/safe_browsing/dmg/generate_test_data.sh test_data/chrome/safe_browsing_dmg
Temporary debugging for  crbug.com/696529 .
/dev/disk0 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *214.7 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS vm682-m1                213.9 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

/dev/disk1 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                                                   +524.3 KB   disk1

DIIsInitialized: returning YES
DIIsInitialized: returning YES
DIBackingStoreNewWithCFURL: entry with
file:///dev/disk1
writeable: false
DIBackingStoreInstantiatorProbe: entry
file:///dev/disk1
writeable: false
DIBackingStoreInstantiatorProbe: probing interface 0 CBSDBackingStore
CBSDBackingStore::newProbe score 100 for file:///dev/disk1
DIBackingStoreInstantiatorProbe: interface  0, score      100, CBSDBackingStore
DIBackingStoreInstantiatorProbe: probing interface 1 CBundleBackingStore
CBundleBackingStore::newProbe score -1000 for file:///dev/disk1
DIBackingStoreInstantiatorProbe: interface  1, score    -1000, CBundleBackingStore
DIBackingStoreInstantiatorProbe: probing interface 2 CRAMBackingStore
CRAMBackingStore::probe: scheme "file": not ram: or ramdisk: scheme.
CRAMBackingStore::probe: score -1000 for file:///dev/disk1
DIBackingStoreInstantiatorProbe: interface  2, score    -1000, CRAMBackingStore
DIBackingStoreInstantiatorProbe: probing interface 3 CCarbonBackingStore
CCarbonBackingStore::newProbe: setting initial rval to +100
CCarbonBackingStore::newProbe: [-1000] cannot get FSRef: FSPathMakeRef() failed -36.
CCarbonBackingStore::newProbe score -1000 for file:///dev/disk1
DIBackingStoreInstantiatorProbe: interface  3, score    -1000, CCarbonBackingStore
DIBackingStoreInstantiatorProbe: probing interface 4 CDevBackingStore
CDevBackingStore::newProbe score 900 for file:///dev/disk1
DIBackingStoreInstantiatorProbe: interface  4, score      900, CDevBackingStore
DIBackingStoreInstantiatorProbe: probing interface 5 CCURLBackingStore
CCURLBackingStore::probe: scheme is: file
CCURLBackingStore::probe: not recognized URL scheme.
CCURLBackingStore::probe: score -1000 for file:///dev/disk1
DIBackingStoreInstantiatorProbe: interface  5, score    -1000, CCURLBackingStore
DIBackingStoreInstantiatorProbe: probing interface 6 CVectoredBackingStore
CVectoredBackingStore::newProbe not "vectored" scheme.
CVectoredBackingStore::newProbe score -1000 for file:///dev/disk1
DIBackingStoreInstantiatorProbe: interface  6, score    -1000, CVectoredBackingStore
DIBackingStoreInstantiatorProbe: selecting CDevBackingStore
DIBackingStoreNewWithCFURL: CDevBackingStore
CDevBackingStore::setURL_Permissions_and_OpenFile: url, path, extension, device inode are set
CDevBackingStore::setPermission: entry with request 1
CBSDBackingStore::setPermission: opening /dev/rdisk1
CBSDBackingStore::OpenLockFriendly: mapping flags 0x00000000 -> 0x00000014 (locks are MANDATORY)
CBSDBackingStore::OpenLockFriendly: setting F_SETBACKINGSTORE
CBSDBackingStore::OpenLockFriendly: F_SETBACKINGSTORE returned errno = 22
(RO lock acquired)
CBSDBackingStore::setPermission: kDI_PERM_READONLY granted
CDevBackingStore::setPermission: CBSDBackingStore granted kDI_PERM_READONLY.
CDevBackingStore::setURL_Permissions_and_OpenFile: permission granted kDI_PERM_READONLY.
CDevBackingStore::setURL_Permissions_and_OpenFile: dev is open
CDevBackingStore::_grabDeviceInfo: got block size
CDevBackingStore::_grabDeviceInfo: ioctl(DKIOCGETMAXBLOCKCOUNTREAD) didn't work - using defaultCDevBackingStore::_grabDeviceInfo: ioctl(DKIOCGETMAXBLOCKCOUNTWRITE) didn't work - using defaultCDevBackingStore::_grabDeviceInfo: got block count
CDevBackingStore device size is 0x0000000000080000 (524288) bytes
CDevBackingStore block size is 0x00000200 (512) bytes
CDevBackingStore device size is 0x00000400 (1024) blocks
CDevBackingStore max read transfer size is 0x00000100 (256) blocks
CDevBackingStore max write transfer size is 0x00000100 (256) blocks
DIBackingStoreNewWithCFURL: instantiator returned 0
DIBackingStoreNewWithCFURL: returning 0
DIResolveURLToBackingStore: processing level 1 encodings.
DIFileEncodingNewWithBackingStore: entry for encoding level 1
DIFileEncodingInstantiatorProbe: entry for level 1
writeable: false
DIFileEncodingInstantiatorProbe: probing level 1 interface 0 CMacBinaryEncoding
00000000: 0000 0000 0000 0000 0000 0000 0000 0000   | ................ |
(repeated 7 times)
hdiutil: fileNameLength          $00000000
hdiutil: resourceForkLength      $00000000
hdiutil: dataForkLength          $00000000
hdiutil: commentLength           $00000000
hdiutil: MacBinary III signature        (0x00000000)
hdiutil: header CRC              $00000000
hdiutil: minimum decoder version $00000000
hdiutil: encoder version         $00000000
no MacBinary III signature - checking for MacBinary I or II
calculated CRC          $00000000
MacBinary II found
final MacBinary sanity check
ERROR kFileNameLength <= 0
failed final MacBinary sanity check...
DIFileEncodingInstantiatorProbe: interface  0, score    -1000, CMacBinaryEncoding
DIFileEncodingInstantiatorProbe: probing level 1 interface 1 CAppleSingleEncoding
00000000: 0000 0000 0000 0000 0000 0000 0000 0000   | ................ |
(repeated 1 times)
00000020: 0000 0000 0000 .... .... .... .... ....   | ................ |
CAppleSingleEncoding::isAppleSingleFile loadAppleSingleHeader failed with error 22
DIFileEncodingInstantiatorProbe: interface  1, score    -1000, CAppleSingleEncoding
DIFileEncodingInstantiatorProbe: probing level 1 interface 2 CEncryptedEncoding
CEncryptedEncoding::copyHeaderInformation: inBackingStore->openDataFork returned 0
CEncryptedEncoding::copyHeaderInformation: inBackingStore->getDataForkLength (stub header) returned 0
CEncryptedEncoding::copyHeaderInformation: backingStore data fork length is 524288
CEncryptedEncoding::copyHeaderInformation: reading V1 header from offset 523012
CEncryptedEncoding::copyHeaderInformation: inBackingStore->readDataFork (stub header) returned 0
CEncryptedEncoding::copyHeaderInformation: not recognized as v1 header
CEncryptedEncoding::copyHeaderInformation: reading V2 header from offset 0
CEncryptedEncoding::copyHeaderInformation: inBackingStore->readDataFork (stub header) returned 0
CEncryptedEncoding::copyHeaderInformation: not recognized as v2 header
(null)
DIFileEncodingInstantiatorProbe: interface  2, score    -1000, CEncryptedEncoding
DIFileEncodingInstantiatorProbe: nothing to select.
DIFileEncodingNewWithBackingStore: probe fails to find appropriate CFileEncoding class.
DIFileEncodingNewWithBackingStore: returning 110
DIResolveURLToBackingStore: level 1 encoding match failed. 110. 
(continuing)
DIResolveURLToBackingStore: processing level 2 encodings.
DIFileEncodingNewWithBackingStore: entry for encoding level 2
DIFileEncodingInstantiatorProbe: entry for level 2
writeable: false
DIFileEncodingInstantiatorProbe: probing level 2 interface 0 CUDIFEncoding
CUDIFEncoding::newProbe: failing because backing store is not UDIF file
DIFileEncodingInstantiatorProbe: interface  0, score    -1000, CUDIFEncoding
DIFileEncodingInstantiatorProbe: nothing to select.
DIFileEncodingNewWithBackingStore: probe fails to find appropriate CFileEncoding class.
DIFileEncodingNewWithBackingStore: returning 110
DIResolveURLToBackingStore: level 2 encoding match failed. 110. 
(continuing)
DIResolveURLToBackingStore: processing level 3 encodings.
DIFileEncodingNewWithBackingStore: entry for encoding level 3
DIFileEncodingInstantiatorProbe: entry for level 3
writeable: false
DIFileEncodingInstantiatorProbe: probing level 3 interface 0 CSegmentedNDIFEncoding
checkTypeCreator:     /    
checkTypeCreator: returning     , score 0
CSegmentedNDIFEncoding::isSegmentedNDIFFile checkTypeCreator failed
DIFileEncodingInstantiatorProbe: interface  0, score    -1000, CSegmentedNDIFEncoding
DIFileEncodingInstantiatorProbe: probing level 3 interface 1 CSegmentedUDIFEncoding
CSegmentedUDIFEncoding::isSegmentedUDIFFile backing store is not of type CUDIFEncoding
DIFileEncodingInstantiatorProbe: interface  1, score    -1000, CSegmentedUDIFEncoding
DIFileEncodingInstantiatorProbe: probing level 3 interface 2 CSegmentedUDIFRawEncoding
DIFileEncodingInstantiatorProbe: interface  2, score    -1000, CSegmentedUDIFRawEncoding
DIFileEncodingInstantiatorProbe: nothing to select.
DIFileEncodingNewWithBackingStore: probe fails to find appropriate CFileEncoding class.
DIFileEncodingNewWithBackingStore: returning 110
DIResolveURLToBackingStore: level 3 encoding match failed. 110. 
(continuing)
DIIsInitialized: returning YES
DIDiskImageNewWithBackingStore: entry with
writeable: false
DIDiskImageInstantiatorProbe: entry
writeable: false
DIDiskImageInstantiatorProbe: probing interface 0 CUDIFDiskImage
CUDIFDiskImage::checkBackingStoreType: backing store is wrong type
DIDiskImageInstantiatorProbe: interface  0, score    -1000, CUDIFDiskImage
DIDiskImageInstantiatorProbe: probing interface 1 CSparseBundleDiskImage
CSparseBundleDiskImage::newProbe: returning 0
DIDiskImageInstantiatorProbe: interface  1, score        0, CSparseBundleDiskImage
DIDiskImageInstantiatorProbe: probing interface 2 CSparseDiskImage
DIDiskImageInstantiatorProbe: interface  2, score        0, CSparseDiskImage
DIDiskImageInstantiatorProbe: probing interface 3 CRawDiskImage
CRawDiskImage: checkBackingStoreType score: 100
DIDiskImageInstantiatorProbe: interface  3, score      100, CRawDiskImage
DIDiskImageInstantiatorProbe: probing interface 4 CDARTDiskImage
DIDiskImageInstantiatorProbe: interface  4, score        0, CDARTDiskImage
DIDiskImageInstantiatorProbe: probing interface 5 CDiskCopy42DiskImage
DIDiskImageInstantiatorProbe: interface  5, score        0, CDiskCopy42DiskImage
DIDiskImageInstantiatorProbe: probing interface 6 CNDIFDiskImage
checkTypeCreator:     /    
checkTypeCreator: returning     , score 0
DIDiskImageInstantiatorProbe: interface  6, score        0, CNDIFDiskImage
DIDiskImageInstantiatorProbe: probing interface 8 CShadowedDiskImage
DIDiskImageInstantiatorProbe: interface  8, score     -100, CShadowedDiskImage
DIDiskImageInstantiatorProbe: probing interface 9 CCFPlugInDiskImage
DIDiskImageInstantiatorProbe: interface  9, score    -1000, CCFPlugInDiskImage
DIDiskImageInstantiatorProbe: probing interface 10 CWrappedDiskImage
DIDiskImageInstantiatorProbe: interface 10, score     -100, CWrappedDiskImage
DIDiskImageInstantiatorProbe: selecting CRawDiskImage
DIDiskImageNewWithBackingStore: CRawDiskImage
checkBackingStoreType returned score 100 type *WAR
CDevBackingStore::setPermission: entry with request 1
CDevBackingStore::setPermission: CBSDBackingStore granted kDI_PERM_READONLY.
DIDiskImageNewWithBackingStore: instantiator returned 0
DIDiskImageNewWithBackingStore: returning 0
process_pmap: creating MKMediaRef
process_pmap: scanning media
process_pmap: MKCFReadMedia() returned -5324: Inappropriate ioctl for device.
===== iso scan =====
(null)
(null)
===============================
none
0:
	partition-name: whole disk
	partition-start: 0
	partition-synthesized: true
	partition-length: 1024
	partition-hint: Apple_HFS
	partition-filesystems:
		HFS+: 
block-size: 512
burnable: true
appendable: true
scheme:     none
block size: 512
_ ## Type_________________ Name_________________ Start___ Size____
+    Apple_HFS             whole disk                   0     1024 

+ synthesized
RAMDISK_VOLUME:  + /dev/disk1
Volume on disk1 failed to mount; if it has a partitioning scheme, use "diskutil mountDisk"
If the volume is damaged, try the "readOnly" option