[Mac] Ignore spell-checker exceptions.

[Mac] Ignore spell-checker exceptions.

Pasteboard corruption or bad third-party code can cause
+[NSSpellChecker sharedSpellChecker] to throw NSExceptions.  Chrome
treats NSExceptions as fatal, because they generally mean things are
awry.  Since this call can happen in response to calls from the
renderer, and the exceptions are not thrown from Chrome code, this
change enables them while retrieving the shared instance.

BUG=92399, 95728
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=113891

[Scott Hess - ex-Googler, 2011-12-09 01:46:28]

http://codereview.chromium.org/8883040/diff/2001/base/mac/scoped_nsexception_...
File base/mac/scoped_nsexception_enabler.h (right):

http://codereview.chromium.org/8883040/diff/2001/base/mac/scoped_nsexception_...
base/mac/scoped_nsexception_enabler.h:49: BASE_EXPORT id
PerformSelectorIgnoringExceptions(NSObject* target, SEL sel);
I wanted to have:

@implementation NSObject (AddlStuff)
- (id)performSelectorIgnoringExceptions:(SEL)aSel;
@end

But no @implementation allowed in base/, unfortunately.  I did prototype
something which ran a base::Callback<id(void)>, but I got nervous about someone
running C++ code in there - I think this is about as close to "Only run
Objective-C code when exceptions enabled" as is reasonable.

http://codereview.chromium.org/8883040/diff/2001/chrome/browser/spellchecker/...
File chrome/browser/spellchecker/spellchecker_mac.mm (right):

http://codereview.chromium.org/8883040/diff/2001/chrome/browser/spellchecker/...
chrome/browser/spellchecker/spellchecker_mac.mm:43: }
I don't _think_ it would be worth memo-izing this, but if you think it would be
worthwhile, that seems reasonable.  I also don't think it is worth histogramming
this, because as far as I can tell, there would be no action item.

http://codereview.chromium.org/8883040/diff/2001/chrome/browser/spellchecker/...
chrome/browser/spellchecker/spellchecker_mac.mm:238: bool CheckSpelling(const
string16& word_to_check, int tag) {
This function was a case where having SharedSpellChecker() return nil seems like
it does the wrong thing.  The length should be 0, so it says there is no
misspelled word, which is wrong.  OTOH, the only other option is to say all
words are misspelled, and I can't think of any reasonable way to message the
user about re-installing their OS or whatever...

[Robert Sesek, 2011-12-09 21:50:38]

lgtm

[commit-bot: I haz the power, 2011-12-09 21:53:56]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/shess@chromium.org/8883040/2001

[commit-bot: I haz the power, 2011-12-09 21:53:59]

Presubmit check for 8883040-2001 failed and returned exit status 1.

Running presubmit commit checks ...

** Presubmit Messages **
If this change requires manual test instructions to QA team, add
TEST=[instructions].

** Presubmit ERRORS **
Missing LGTM from an OWNER for:
base/mac/scoped_nsexception_enabler.h,base/mac/scoped_nsexception_enabler.mm

[Scott Hess - ex-Googler, 2011-12-09 21:58:09]

OWNERS, from the depths of hell, I stab at thee.

Nico, can I borrow your rubber stamp for the base/mac/ change?

[Nico, 2011-12-09 22:01:07]

stamp lgtm

http://codereview.chromium.org/8883040/diff/2001/base/mac/scoped_nsexception_...
File base/mac/scoped_nsexception_enabler.h (right):

http://codereview.chromium.org/8883040/diff/2001/base/mac/scoped_nsexception_...
base/mac/scoped_nsexception_enabler.h:46: // Calls [target performSelector:sel]
with fatal-exceptions turned
// Calls -performSelector:sel …

[Scott Hess - ex-Googler, 2011-12-09 22:05:22]

On 2011/12/09 22:01:07, Nico wrote:
> stamp lgtm
> 
>
http://codereview.chromium.org/8883040/diff/2001/base/mac/scoped_nsexception_...
> File base/mac/scoped_nsexception_enabler.h (right):
> 
>
http://codereview.chromium.org/8883040/diff/2001/base/mac/scoped_nsexception_...
> base/mac/scoped_nsexception_enabler.h:46: // Calls [target
performSelector:sel]
> with fatal-exceptions turned
> // Calls -performSelector:sel …

Wait, what?  "Calls -performSelector:sel on target"?  "Calls -performSelector:
on target with sel"?

I'll assume that you're taking exception to using "Calls" in reference to a code
snippet, and changed to "Executes".

[commit-bot: I haz the power, 2011-12-09 22:05:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/shess@chromium.org/8883040/6002

[commit-bot: I haz the power, 2011-12-10 00:17:07]

Change committed as 113891