Remove CaseInsensitiveCompare from string_util.h

There were a number of callers in net using this for HTTP headers. I think
these callers actually just need ASCII case-insensitive comparisons so these
were changed.

The omnibox code used this functor. I added a new omnibox-specific one which
does not have the locale issues of the old string_util one, but which still
has the UTF-16 and combining accent issues (described in great detail in
the comment for this).

The Windows installer code can't depend on ICU so it calls the Win32 function
to do case-insensitive comparisons. This should match the system comparison
for registry keys better anyway.

I also changed a caller of StartsWith to use this version. I wrote this
StartsWith call using ToLower in a previous patch, but it turns out that the
lengths of case-mapped strings do change in practice, making the offset
computations of the suyrrounding code incorrect. This new version will be
like the old version (will miss some cases of case-insensitive equality) but
will handle 0x80-0xFF properly.

BUG=24917

Review URL: https://codereview.chromium.org/1230583014

Cr-Commit-Position: refs/heads/master@{#338624}

1 files changed, 3 insertions, 2 deletions

diff --git a/win8/test/ui_automation_client.cc b/win8/test/ui_automation_client.cc
index 9aa4237..22c1af1 100644
--- a/win8/test/ui_automation_client.cc
+++ b/win8/test/ui_automation_client.cc
@@ -323,10 +323,11 @@ void UIAutomationClient::Context::HandleWindowOpen(
 
   base::string16 class_name(V_BSTR(var.ptr()));
 
-  // Window class names are atoms, which are case-insensitive.
+  // Window class names are atoms, which are case-insensitive. Assume that
+  // the window in question only needs ASCII case-insensitivity.
   if (class_name.size() == class_name_.size() &&
       std::equal(class_name.begin(), class_name.end(), class_name_.begin(),
-                 base::CaseInsensitiveCompare<wchar_t>())) {
+                 base::CaseInsensitiveCompareASCII<wchar_t>())) {
     RemoveWindowObserver();
     ProcessWindow(window);
   }