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/cpdfsdk_pageview.h b/fpdfsdk/cpdfsdk_pageview.h
index 00e90d7..b86f305 100644
--- a/fpdfsdk/cpdfsdk_pageview.h
+++ b/fpdfsdk/cpdfsdk_pageview.h
@@ -61,8 +61,8 @@
     return m_pFormFillEnv.Get();
   }
 
-  CFX_WideString GetSelectedText();
-  void ReplaceSelection(const CFX_WideString& text);
+  WideString GetSelectedText();
+  void ReplaceSelection(const WideString& text);
 
   bool OnFocus(const CFX_PointF& point, uint32_t nFlag);
   bool OnLButtonDown(const CFX_PointF& point, uint32_t nFlag);