Remove special case in HTTP header flattening in WebURLLoaderImpl

Remove special case in HTTP header flattening in WebURLLoaderImpl

Following https://chromiumcodereview.appspot.com/318673002/ blink will no
longer be setting cache headers, so the special case that skips over cache
headers is not needed anymore.

BUG=376025

[clamy, 2014-06-04 11:53:11]

@ppi: Yay 5th patch! PTAL

[ppi, 2014-06-04 16:24:31]

yay lgtm, thanks!

[clamy, 2014-06-04 16:40:23]

@jam: PTAL. This is the last patch aimed at removing the setting of cache
headers in Blink.

[jam, 2014-06-04 18:06:15]

lgtm

[clamy, 2014-06-05 19:43:14]

The CQ bit was checked by clamy@chromium.org

[commit-bot: I haz the power, 2014-06-05 19:45:39]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/clamy@chromium.org/316883002/1

[commit-bot: I haz the power, 2014-06-06 00:53:12]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)
  linux_chromium_chromeos_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_clang_...)
  linux_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_rel/bu...)
  mac_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_compile_...)
  mac_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_rel/buil...)
  mac_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu/builds/13571)

[commit-bot: I haz the power, 2014-06-06 01:04:17]

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

[commit-bot: I haz the power, 2014-06-06 01:04:18]

Try jobs failed on following builders:
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)

[clamy, 2014-06-06 09:22:58]

The CQ bit was checked by clamy@chromium.org

[commit-bot: I haz the power, 2014-06-06 09:25:52]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/clamy@chromium.org/316883002/20001

[commit-bot: I haz the power, 2014-06-06 12:55:56]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_aosp on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_aosp/builds/8...)
  android_chromium_gn_compile_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_chromium_gn_c...)
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)
  android_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/19...)
  linux_chromium_chromeos_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_chromeos_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_clang_...)
  linux_chromium_gn_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_gn_rel...)
  linux_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_rel/bu...)
  mac_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_compile_...)
  mac_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_rel/buil...)
  win_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_compile_...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)
  win_chromium_x64_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_x64_rel/...)
  linux_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu/builds/...)
  mac_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu/builds/13823)
  win_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu/builds/16934)

[commit-bot: I haz the power, 2014-06-06 13:05:40]

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

[commit-bot: I haz the power, 2014-06-06 13:05:41]

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

[clamy, 2014-06-06 13:51:45]

The CQ bit was checked by clamy@chromium.org

[commit-bot: I haz the power, 2014-06-06 13:52:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/clamy@chromium.org/316883002/40001

[commit-bot: I haz the power, 2014-06-06 17:32:36]

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

[commit-bot: I haz the power, 2014-06-06 17:32:37]

Could not make sense out of svn commit message.