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, 10 insertions, 0 deletions

diff --git a/testing/resources/javascript/globals_expected.txt b/testing/resources/javascript/globals_expected.txt
index ddaa00cd09..fcebd70466 100644
--- a/testing/resources/javascript/globals_expected.txt
+++ b/testing/resources/javascript/globals_expected.txt
@@ -45,6 +45,7 @@ Alert:   string_var = undefined
 Alert:   object_var = undefined
 Alert:   null_var = undefined
 Alert:   undefined_var = undefined
+Alert: For undefined_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
 Alert: ************ After Setup and Persist false ************
 Alert: Enumerable Globals:
 Alert:   setPersistent = function setPersistent() { [native code] }, own property = true
@@ -68,6 +69,14 @@ Alert:     green
 Alert:     blue
 Alert:   null_var = null
 Alert:   undefined_var = undefined
+Alert: For true_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
+Alert: For false_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
+Alert: For zero_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
+Alert: For number_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
+Alert: For string_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
+Alert: For object_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
+Alert: For null_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
+Alert: For undefined_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
 Alert: ************ After Delete and Persist ************
 Alert: Enumerable Globals:
 Alert:   setPersistent = function setPersistent() { [native code] }, own property = true
@@ -80,6 +89,7 @@ Alert:   string_var = undefined
 Alert:   object_var = undefined
 Alert:   null_var = undefined
 Alert:   undefined_var = undefined
+Alert: For undefined_var: Set Persistent: ERROR: global.setPersistent: Global value not found.
 Alert: ************ After Setup and Persist true ************
 Alert: Enumerable Globals:
 Alert:   setPersistent = function setPersistent() { [native code] }, own property = true