Modify the stack signature for bug 70031 slightly to match a new stack signat...

Modify the stack signature for bug 70031 slightly to match a new stack signature found.

The present pattern does not have a single quotation mark after destructor. 

Below is taken from the log (with newlines added for the readability)

Checking new crashes...
INFO: NEW stack trace signature found:
webcore::shadowdata::`scalar deleting destructor'___
webcore::shadowdata::`scalar deleting destructor'___
webcore::shadowdata::`scalar deleting destructor'___
webcore::shadowdata::`scalar deleting destructor'___
..... and goes on ...

INFO: known stack trace signature found.
(match REGEX, tcmalloc.+webcore.+)


REGRESSION: NEW crash stack traces found
--------------------
Repro information:
UI sequence: SetUp,newtab,navigate,openwindow,navigate,pagedown,showbookmarks,back,navigate,back,navigate

Stack trace:
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0xa
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11
chrome_2590000!WebCore::ShadowData::`scalar deleting destructor'+0x11


BUG=70031
TEST=NONE
TBR=huanr

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=74707