GURL::Replacements methods accept a StringPiece instead of std::string&.

GURL::Replacements methods accept a StringPiece instead of std::string&.

Previously, it was unsafe to pass a char* because it would be implicitly
converted to a string with a very short lifetime. Now, you can safely
pass a char* as long as the memory pointed to by the char* outlives the
Replacements (which is always true for string literals).

All existing usage of Replacements should continue to work as usual.

Updated every call to Replacements Set*Str methods that that could be
simplified by the new StringPiece API (for example, passing string
literals directly, instead of copying them into a string object).

Internally, renamed StdStringReplacements to StringPieceReplacements.

BUG=454274
Committed: https://crrev.com/77752c3e55c59747a62a362799ac6de5ff56fd45
Cr-Commit-Position: refs/heads/master@{#314771}

[Matt Giuca, 2015-02-02 06:33:52]

mgiuca@chromium.org changed reviewers:
+ brettw@chromium.org

[Matt Giuca, 2015-02-02 06:33:53]

See bug for an explanation.

brettw: For an initial review (in particular, of the url/* changes). Let me know
if you want me to add more specific owners to review the giant amount of changes
to the callers.

Take your time to get back to me on this one.

[brettw, 2015-02-03 01:27:12]

lgtm

[Matt Giuca, 2015-02-04 00:23:37]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2015-02-04 00:24:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/889463003/40001

[commit-bot: I haz the power, 2015-02-04 00:28:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-02-04 00:28:03]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Matt Giuca, 2015-02-05 06:32:58]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2015-02-05 06:33:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/889463003/60001

[commit-bot: I haz the power, 2015-02-05 07:31:56]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-02-05 07:32:47]

Patchset 4 (id:??) landed as
https://crrev.com/77752c3e55c59747a62a362799ac6de5ff56fd45
Cr-Commit-Position: refs/heads/master@{#314771}