Return error information from pdfium to JS.

This implements the previously unimplemented JS_Error() function.

Along the way:
- fix some IWYU when the include order in global.cpp was perturbed.
- remove some uses of JS_ErrorString, to increase transparency.
- use vp.IsSetting() in place of !vp.IsGetting() for clarity.
- specify an error string on several error return paths.
- add an error string for writing readonly properties.
- rename an error string constant to reflect the actual message.
- replace calls to variadic Format() with a function doing string appends.
- remove unused JS_GetClassName()

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/963193003

1 files changed, 5 insertions, 1 deletions

diff --git a/fpdfsdk/include/javascript/resource.h b/fpdfsdk/include/javascript/resource.h
index 058b5fd893..8f0a25061e 100644
--- a/fpdfsdk/include/javascript/resource.h
+++ b/fpdfsdk/include/javascript/resource.h
@@ -26,8 +26,12 @@ class CJS_Context;
 #define IDS_STRING_RUN                  25630
 #define IDS_STRING_JSPRINT1             25632
 #define IDS_STRING_JSPRINT2             25633
-#define IDS_JSPARAM_INCORRECT           25635
+#define IDS_STRING_JSNOGLOBAL           25635
+#define IDS_STRING_JSREADONLY           25636
 
 CFX_WideString JSGetStringFromID(CJS_Context* pContext, FX_UINT id);
+CFX_WideString JSFormatErrorString(const char* class_name,
+                                   const char* property_name,
+                                   const CFX_WideString& details);
 
 #endif  // FPDFSDK_INCLUDE_JAVASCRIPT_RESOURCE_H_