Convert string class names

Automated using git grep & sed.
Replace StringC classes with StringView classes.
Remove the CFX_ prefix and put string classes in fxcrt namespace.
Change AsStringC() to AsStringView().
Rename tests from TEST(fxcrt, *String*Foo) to TEST(*String*,
Foo).
Couple of tests needed to have their names regularlized.

BUG=pdfium:894

Change-Id: I7ca038685c8d803795f3ed02545124f7a224c83d
Reviewed-on: https://pdfium-review.googlesource.com/14151
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
diff --git a/fpdfsdk/javascript/report.cpp b/fpdfsdk/javascript/report.cpp
index c9c986d..4550943 100644
--- a/fpdfsdk/javascript/report.cpp
+++ b/fpdfsdk/javascript/report.cpp
@@ -29,7 +29,7 @@
 bool Report::writeText(CJS_Runtime* pRuntime,
                        const std::vector<CJS_Value>& params,
                        CJS_Value& vRet,
-                       CFX_WideString& sError) {
+                       WideString& sError) {
   // Unsafe, not supported.
   return true;
 }
@@ -37,7 +37,7 @@
 bool Report::save(CJS_Runtime* pRuntime,
                   const std::vector<CJS_Value>& params,
                   CJS_Value& vRet,
-                  CFX_WideString& sError) {
+                  WideString& sError) {
   // Unsafe, not supported.
   return true;
 }