Support inexact path matching when extracting terms from Template URL.

Support inexact path matching when extracting terms from Template URL.

This adds pattern {google:ignorePathEnding} which can be used for
writing alternate URLs to avoid exact path matching. For example,
http://foo/search/{searchTerms}/extra/{google:ignorePathEnding}

BUG=611265
TEST=components_unittests:TemplateURLTest.HostAndSearchTermKey,
                                          ExtractSearchTermsFromURLPath

R=pkasting@chromium.org

[Peter Kasting, 2016-05-12 11:32:13]

See discussion on bug.

[Vitaly Baranov, 2016-05-12 12:43:28]

On 2016/05/12 11:32:13, Peter Kasting wrote:
> See discussion on bug.

I think some parts of this CL could be useful as refactoring even without adding
the "{google:ignorePathEnding}" pattern. I mean the following changes:
1) remove variable TemplateURLRef::search_term_position_in_path_ because
search_term_value_prefix_ & search_term_value_suffix_ can be used instead.
2) rewrite FindSearchTermsInPath() for consistency with FindSearchTermsKey()
which was recently rewritten in
https://codereview.chromium.org/1902263002/diff/20001/components/search_engin...
3) combine two tests TemplateURLTest.HostAndSearchTermKey and
TemplateURLTest.SearchTermKeyLocation into a single extended test with more test
cases added.
4) fix minor bug in TemplateURLRef::InvalidateCachedValues().

[Vitaly Baranov, 2016-05-12 15:16:23]

On 2016/05/12 12:43:28, Vitaly Baranov wrote:
> On 2016/05/12 11:32:13, Peter Kasting wrote:
> > See discussion on bug.
> 
> I think some parts of this CL could be useful as refactoring even without
adding
> the "{google:ignorePathEnding}" pattern. I mean the following changes:
> 1) remove variable TemplateURLRef::search_term_position_in_path_ because
> search_term_value_prefix_ & search_term_value_suffix_ can be used instead.
> 2) rewrite FindSearchTermsInPath() for consistency with FindSearchTermsKey()
> which was recently rewritten in
>
https://codereview.chromium.org/1902263002/diff/20001/components/search_engin...
> 3) combine two tests TemplateURLTest.HostAndSearchTermKey and
> TemplateURLTest.SearchTermKeyLocation into a single extended test with more
test
> cases added.
> 4) fix minor bug in TemplateURLRef::InvalidateCachedValues().

Please take a look at https://codereview.chromium.org/1978553002/