Revert of Switch WTF::find on LChar to use memchr.

Revert of Switch WTF::find on LChar to use memchr. (patchset #1 id:1 of https://codereview.chromium.org/1948543004/ )

Reason for revert:
LSAN and MSAN bots appear unhappy:

http/tests/media/media-source/mediasource-is-type-supported.html

crash log for renderer (pid <unknown>):
STDOUT: <empty>
STDERR: =================================================================
STDERR: ==4==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6030000982af at pc 0x00000045811f bp 0x7fff2f309830 sp 0x7fff2f308fe0
STDERR: READ of size 5006 at 0x6030000982af thread T0 (content_shell)
STDERR:     #0 0x45811e in memchr ??:0
STDERR:     #1 0x3c5c419 in find third_party/WebKit/Source/wtf/text/StringImpl.h:532:9
STDERR:     #2 0x3c5c419 in find third_party/WebKit/Source/wtf/text/StringImpl.h:660:0
STDERR:     #3 0x3c5c419 in find third_party/WebKit/Source/wtf/text/WTFString.h:214:0
STDERR:     #4 0x3c5c419 in find third_party/WebKit/Source/wtf/text/WTFString.h:215:0
STDERR:     #5 0x3c5c419 in parameter third_party/WebKit/Source/platform/ContentType.cpp:50:0
STDERR:     #6 0x8d64b7d in isTypeSupported third_party/WebKit/Source/modules/mediasource/MediaSource.cpp:244:33
STDERR:     #7 0x9251198 in isTypeSupportedMethod ./out/Release/gen/blink/bindings/modules/v8/V8MediaSource.cpp:234:32
STDERR:     #8 0x9251198 in isTypeSupportedMethodCallback ./out/Release/gen/blink/bindings/modules/v8/V8MediaSource.cpp:239:0
STDERR:     #9 0x444b759 in Call v8/src/api-arguments.cc:16:3

(https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_ASAN/24421/layout-test-results/results.html)

Original issue's description:
> Switch WTF::find on LChar to use memchr.
>
> BUG=607208
>
> Committed: https://crrev.com/c9f9af30569ac2cd353e234f569052db6ab436f4
> Cr-Commit-Position: refs/heads/master@{#397568}

TBR=thakis@chromium.org,jbroman@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=607208
Committed: https://crrev.com/08438794f10a999c095ad758cae293c7a1beff0f
Cr-Commit-Position: refs/heads/master@{#397664}

[fs, 2016-06-03 08:23:04]

The CQ bit was checked by fs@opera.com

[fs, 2016-06-03 08:23:05]

Created Revert of Switch WTF::find on LChar to use memchr.

[commit-bot: I haz the power, 2016-06-03 08:23:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2036993002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2036993002/1

[commit-bot: I haz the power, 2016-06-03 08:23:55]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-03 08:26:32]

Description was changed from

==========
Revert of Switch WTF::find on LChar to use memchr. (patchset #1 id:1 of
https://codereview.chromium.org/1948543004/ )

Reason for revert:
LSAN and MSAN bots appear unhappy:

http/tests/media/media-source/mediasource-is-type-supported.html

crash log for renderer (pid <unknown>):
STDOUT: <empty>
STDERR: =================================================================
STDERR: ==4==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x6030000982af at pc 0x00000045811f bp 0x7fff2f309830 sp 0x7fff2f308fe0
STDERR: READ of size 5006 at 0x6030000982af thread T0 (content_shell)
STDERR:     #0 0x45811e in memchr ??:0
STDERR:     #1 0x3c5c419 in find
third_party/WebKit/Source/wtf/text/StringImpl.h:532:9
STDERR:     #2 0x3c5c419 in find
third_party/WebKit/Source/wtf/text/StringImpl.h:660:0
STDERR:     #3 0x3c5c419 in find
third_party/WebKit/Source/wtf/text/WTFString.h:214:0
STDERR:     #4 0x3c5c419 in find
third_party/WebKit/Source/wtf/text/WTFString.h:215:0
STDERR:     #5 0x3c5c419 in parameter
third_party/WebKit/Source/platform/ContentType.cpp:50:0
STDERR:     #6 0x8d64b7d in isTypeSupported
third_party/WebKit/Source/modules/mediasource/MediaSource.cpp:244:33
STDERR:     #7 0x9251198 in isTypeSupportedMethod
./out/Release/gen/blink/bindings/modules/v8/V8MediaSource.cpp:234:32
STDERR:     #8 0x9251198 in isTypeSupportedMethodCallback
./out/Release/gen/blink/bindings/modules/v8/V8MediaSource.cpp:239:0
STDERR:     #9 0x444b759 in Call v8/src/api-arguments.cc:16:3

(https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_ASA...)

Original issue's description:
> Switch WTF::find on LChar to use memchr.
> 
> BUG=607208
> 
> Committed: https://crrev.com/c9f9af30569ac2cd353e234f569052db6ab436f4
> Cr-Commit-Position: refs/heads/master@{#397568}

TBR=thakis@chromium.org,jbroman@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=607208
==========

to

==========
Revert of Switch WTF::find on LChar to use memchr. (patchset #1 id:1 of
https://codereview.chromium.org/1948543004/ )

Reason for revert:
LSAN and MSAN bots appear unhappy:

http/tests/media/media-source/mediasource-is-type-supported.html

crash log for renderer (pid <unknown>):
STDOUT: <empty>
STDERR: =================================================================
STDERR: ==4==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x6030000982af at pc 0x00000045811f bp 0x7fff2f309830 sp 0x7fff2f308fe0
STDERR: READ of size 5006 at 0x6030000982af thread T0 (content_shell)
STDERR:     #0 0x45811e in memchr ??:0
STDERR:     #1 0x3c5c419 in find
third_party/WebKit/Source/wtf/text/StringImpl.h:532:9
STDERR:     #2 0x3c5c419 in find
third_party/WebKit/Source/wtf/text/StringImpl.h:660:0
STDERR:     #3 0x3c5c419 in find
third_party/WebKit/Source/wtf/text/WTFString.h:214:0
STDERR:     #4 0x3c5c419 in find
third_party/WebKit/Source/wtf/text/WTFString.h:215:0
STDERR:     #5 0x3c5c419 in parameter
third_party/WebKit/Source/platform/ContentType.cpp:50:0
STDERR:     #6 0x8d64b7d in isTypeSupported
third_party/WebKit/Source/modules/mediasource/MediaSource.cpp:244:33
STDERR:     #7 0x9251198 in isTypeSupportedMethod
./out/Release/gen/blink/bindings/modules/v8/V8MediaSource.cpp:234:32
STDERR:     #8 0x9251198 in isTypeSupportedMethodCallback
./out/Release/gen/blink/bindings/modules/v8/V8MediaSource.cpp:239:0
STDERR:     #9 0x444b759 in Call v8/src/api-arguments.cc:16:3

(https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_ASA...)

Original issue's description:
> Switch WTF::find on LChar to use memchr.
>
> BUG=607208
>
> Committed: https://crrev.com/c9f9af30569ac2cd353e234f569052db6ab436f4
> Cr-Commit-Position: refs/heads/master@{#397568}

TBR=thakis@chromium.org,jbroman@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=607208

Committed: https://crrev.com/08438794f10a999c095ad758cae293c7a1beff0f
Cr-Commit-Position: refs/heads/master@{#397664}
==========

[commit-bot: I haz the power, 2016-06-03 08:26:33]

Patchset 1 (id:??) landed as
https://crrev.com/08438794f10a999c095ad758cae293c7a1beff0f
Cr-Commit-Position: refs/heads/master@{#397664}