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

4 files changed, 64 insertions, 32 deletions

diff --git a/testing/resources/javascript/document_props.in b/testing/resources/javascript/document_props.in
index 8ab7e3d566..c628fafad2 100644
--- a/testing/resources/javascript/document_props.in
+++ b/testing/resources/javascript/document_props.in
@@ -105,27 +105,27 @@ var document_props = [
 ];
 
 function testGetProps(props) {
-  try {
-    app.alert('*** Getting properties ***');
-    for (var i = 0; i < props.length; ++i) {
-        var expr1 = "this." + props[i];
-        var expr2 = "typeof " + expr1;
-        app.alert(expr1 + " is " + eval(expr2) + ' ' + eval(expr1));
+  app.alert('*** Getting properties ***');
+  for (var i = 0; i < props.length; ++i) {
+    try {
+      var expr1 = "this." + props[i];
+      var expr2 = "typeof " + expr1;
+      app.alert(expr1 + " is " + eval(expr2) + ' ' + eval(expr1));
+    } catch (e) {
+      app.alert("ERROR: " + e.toString());
     }
-  } catch (e) {
-    app.alert("ERROR: " + e.toString());
   }
 }
 
 function testSetProps(props) {
-  try {
-    app.alert('*** Setting properties ***');
-    for (var i = 0; i < props.length; ++i) {
-        var expr1 = "this." + props[i] + ' = 3;'
-        app.alert(expr1 + " yields " + eval(expr1));
+  app.alert('*** Setting properties ***');
+  for (var i = 0; i < props.length; ++i) {
+    try {
+      var expr1 = "this." + props[i] + ' = 3;'
+      app.alert(expr1 + " yields " + eval(expr1));
+    } catch (e) {
+      app.alert("ERROR: " + e.toString());
     }
-  } catch (e) {
-    app.alert("ERROR: " + e.toString());
   }
 }
 
diff --git a/testing/resources/javascript/document_props_expected.txt b/testing/resources/javascript/document_props_expected.txt
index 38bea97acb..728d2455e1 100644
--- a/testing/resources/javascript/document_props_expected.txt
+++ b/testing/resources/javascript/document_props_expected.txt
@@ -41,10 +41,10 @@ Alert: this.creationDate = 3; yields 3
 Alert: this.creator = 3; yields 3
 Alert: this.delay = 3; yields 3
 Alert: this.dirty = 3; yields 3
-Alert: this.documentFileName = 3; yields 3
+Alert: ERROR: Document.documentFileName: Cannot assign to readonly property.
 Alert: this.external = 3; yields 3
-Alert: this.filesize = 3; yields 3
-Alert: this.icons = 3; yields 3
+Alert: ERROR: Document.filesize: Cannot assign to readonly property.
+Alert: ERROR: Document.icons: Cannot assign to readonly property.
 Alert: this.info = 3; yields 3
 Alert: this.keywords = 3; yields 3
 Alert: this.layout = 3; yields 3
@@ -52,12 +52,12 @@ Alert: this.media = 3; yields 3
 Alert: this.modDate = 3; yields 3
 Alert: this.mouseX = 3; yields 3
 Alert: this.mouseY = 3; yields 3
-Alert: this.numFields = 3; yields 3
-Alert: this.numPages = 3; yields 3
+Alert: ERROR: Document.numFields: Cannot assign to readonly property.
+Alert: ERROR: Document.numPages: Cannot assign to readonly property.
 Goto Page: 3
 Alert: this.pageNum = 3; yields 3
 Alert: this.pageWindowRect = 3; yields 3
-Alert: this.path = 3; yields 3
+Alert: ERROR: Document.path: Cannot assign to readonly property.
 Alert: this.producer = 3; yields 3
 Alert: this.subject = 3; yields 3
 Alert: this.title = 3; yields 3
diff --git a/testing/resources/javascript/globals.in b/testing/resources/javascript/globals.in
index 6d2f3ca241..4812101e7a 100644
--- a/testing/resources/javascript/globals.in
+++ b/testing/resources/javascript/globals.in
@@ -63,21 +63,34 @@ var props_to_test = [
 function setup_global() {
   for (var i = 0; i < props_to_test.length; ++i) {
     var prop = props_to_test[i];
-    global[prop.name] = prop.value;
+    try {
+      global[prop.name] = prop.value;
+    } catch (e) {
+      app.alert("For " + prop.name + ": Setup: ERROR: " + e.toString());
+    }
   }
 }
 
 function delete_global() {
   for (var i = 0; i < props_to_test.length; ++i) {
     var prop = props_to_test[i];
-    delete global[prop.name];
+    try {
+      delete global[prop.name];
+    } catch (e) {
+      app.alert("For " + prop.name + ": Delete: ERROR: " + e.toString());
+    }
   }
 }
 
 function persist_global(should_persist) {
   for (var i = 0; i < props_to_test.length; ++i) {
     var prop = props_to_test[i];
-    global.setPersistent(prop.name, should_persist);
+    try {
+      global.setPersistent(prop.name, should_persist);
+    } catch (e) {
+      app.alert("For " + prop.name +
+                ": Set Persistent: ERROR: " + e.toString());
+    }
   }
 }
 
@@ -85,18 +98,27 @@ function dump_global(msg) {
   app.alert("************ " + msg + " ************");
   app.alert("Enumerable Globals:");
   for (var name in global) {
-    app.alert("  " + name + " = " + global[name] +
-              ", own property = " + global.hasOwnProperty(name));
+    try {
+      app.alert("  " + name + " = " + global[name] +
+                ", own property = " + global.hasOwnProperty(name));
+    } catch (e) {
+      app.alert("For " + name + ": Dump: ERROR: " + e.toString());
+    }
   }
   app.alert("Expected Globals:");
   for (var i = 0; i < props_to_test.length; ++i) {
     var prop = props_to_test[i];
-    var actual = global[prop.name];
-    app.alert("  " + prop.name + " = " + actual);
-    if (actual != null && typeof actual == "object") {
-      app.alert("    " + actual.colors[0]);
-      app.alert("    " + actual.colors[1]);
-      app.alert("    " + actual.colors[2]);
+    try {
+      var actual = global[prop.name];
+      app.alert("  " + prop.name + " = " + actual);
+      if (actual != null && typeof actual == "object") {
+        app.alert("    " + actual.colors[0]);
+        app.alert("    " + actual.colors[1]);
+        app.alert("    " + actual.colors[2]);
+      }
+    } catch (e) {
+      app.alert("For " + prop.name +
+                ": Dump Expected: ERROR: " + e.toString());
     }
   }
 }
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