Oilpan: Allowing hashing of RawPtr.

Oilpan: Allowing hashing of RawPtr.

R=erik.corry@gmail.com, eseidel@chromium.org, jochen@chromium.org
BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=168309

[Mads Ager (chromium), 2014-03-03 10:13:42]

Eric could you have a look at the wtf changes. Jochen is on vacation. Thanks!

[Erik Corry, 2014-03-03 10:17:51]

lgtm

[tkent, 2014-03-03 10:19:57]

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h
File Source/wtf/HashTraits.h (left):

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h#oldc...
Source/wtf/HashTraits.h:89: static IteratorConstGetType
getToConstGetConversion(const T* x) { return x; }
Why do you remove this line?

[Mads Ager (chromium), 2014-03-03 10:20:50]

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h
File Source/wtf/HashTraits.h (left):

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h#oldc...
Source/wtf/HashTraits.h:89: static IteratorConstGetType
getToConstGetConversion(const T* x) { return x; }
On 2014/03/03 10:19:57, tkent wrote:
> Why do you remove this line?

Because it is unused in the code base. :)

[tkent, 2014-03-03 10:23:42]

wtf lgtm.

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h
File Source/wtf/HashTraits.h (left):

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h#oldc...
Source/wtf/HashTraits.h:89: static IteratorConstGetType
getToConstGetConversion(const T* x) { return x; }
On 2014/03/03 10:20:50, Mads Ager (chromium) wrote:
> On 2014/03/03 10:19:57, tkent wrote:
> > Why do you remove this line?
> 
> Because it is unused in the code base. :)

I see.  I don't think we should include this change in this CL because it's
unrelated.

[Mikhail, 2014-03-03 10:25:55]

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h
File Source/wtf/HashTraits.h (right):

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h#newc...
Source/wtf/HashTraits.h:200: typedef T* const IteratorConstReferenceType;
could I ask why 'IteratorReferenceType' and 'IteratorConstReferenceType' are
declared in so different way?

[Mads Ager (chromium), 2014-03-03 10:29:00]

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h
File Source/wtf/HashTraits.h (right):

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h#newc...
Source/wtf/HashTraits.h:200: typedef T* const IteratorConstReferenceType;
On 2014/03/03 10:25:56, mikhail.pozdnyakov wrote:
> could I ask why 'IteratorReferenceType' and 'IteratorConstReferenceType' are
> declared in so different way?

Yes, there is no reason for the extra indirection for the const reference type.
A raw pointer is usable exactly as a raw pointer and for the const version we
can cut out the indirection safely which is better for performance.

[Mads Ager (chromium), 2014-03-03 10:30:34]

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h
File Source/wtf/HashTraits.h (left):

https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h#oldc...
Source/wtf/HashTraits.h:89: static IteratorConstGetType
getToConstGetConversion(const T* x) { return x; }
On 2014/03/03 10:23:43, tkent wrote:
> On 2014/03/03 10:20:50, Mads Ager (chromium) wrote:
> > On 2014/03/03 10:19:57, tkent wrote:
> > > Why do you remove this line?
> > 
> > Because it is unused in the code base. :)
> 
> I see.  I don't think we should include this change in this CL because it's
> unrelated.

It seems to me that removing dead code is always a good idea. I'm cutting it out
in this change so I don't have to put it in for new code when I know that it is
dead anyway. :)

[Mads Ager (chromium), 2014-03-03 10:30:41]

The CQ bit was checked by ager@chromium.org

[commit-bot: I haz the power, 2014-03-03 10:30:52]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ager@chromium.org/183833009/1

[haraken, 2014-03-03 10:35:30]

LGTM

[Mikhail, 2014-03-03 11:07:37]

On 2014/03/03 10:29:00, Mads Ager (chromium) wrote:
> https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h
> File Source/wtf/HashTraits.h (right):
> 
>
https://codereview.chromium.org/183833009/diff/1/Source/wtf/HashTraits.h#newc...
> Source/wtf/HashTraits.h:200: typedef T* const IteratorConstReferenceType;
> On 2014/03/03 10:25:56, mikhail.pozdnyakov wrote:
> > could I ask why 'IteratorReferenceType' and 'IteratorConstReferenceType' are
> > declared in so different way?
> 
> Yes, there is no reason for the extra indirection for the const reference
type.
> A raw pointer is usable exactly as a raw pointer and for the const version we
> can cut out the indirection safely which is better for performance.

sounds good :) thanks

[wibling-chromium, 2014-03-03 11:56:01]

lgtm

[commit-bot: I haz the power, 2014-03-03 13:00:32]

Change committed as 168309