DevTools: move DevToolsAgent/Client into content.

BUG=84078
TEST=

Review URL: http://codereview.chromium.org/7461019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93596 0039d316-1c4b-4281-b951-d872f2087c98
bool IsInBrowserThumbnailingEnabled() {
#if defined(OS_LINUX) || defined(OS_CHROMEOS)
  return true;
#else
  return CommandLine::ForCurrentProcess()->HasSwitch(
      kEnableInBrowserThumbnailing);
#endif
}

bool IsInBrowserThumbnailingEnabled() {
#if defined(OS_LINUX) || defined(OS_CHROMEOS)
  return true;
#else
  return CommandLine::ForCurrentProcess()->HasSwitch(
      kEnableInBrowserThumbnailing);
#endif
}
