Set appropriate defaults for webview options (#12271)

* Persist defaults to webPreferences object to JS land can read the inferred values instead of just user defined values

* Test inherited default propogation

* Refactor to remove coupling from fetching values and defaults

* Test description type

* Fix up tests

atom/browser/api/atom_api_web_contents.cc

@@ -1825,6 +1825,14 @@ v8::Local<v8::Value> WebContents::GetWebPreferences(v8::Isolate* isolate) {
   return mate::ConvertToV8(isolate, *web_preferences->web_preferences());
 }
 
+v8::Local<v8::Value> WebContents::GetLastWebPreferences(v8::Isolate* isolate) {
+  WebContentsPreferences* web_preferences =
+      WebContentsPreferences::FromWebContents(web_contents());
+  if (!web_preferences)
+    return v8::Null(isolate);
+  return mate::ConvertToV8(isolate, *web_preferences->last_web_preferences());
+}
+
 v8::Local<v8::Value> WebContents::GetOwnerBrowserWindow() {
   if (owner_window())
     return BrowserWindow::From(isolate(), owner_window());
@@ -1976,6 +1984,7 @@ void WebContents::BuildPrototype(v8::Isolate* isolate,
       .SetMethod("_getZoomFactor", &WebContents::GetZoomFactor)
       .SetMethod("getType", &WebContents::GetType)
       .SetMethod("getWebPreferences", &WebContents::GetWebPreferences)
+      .SetMethod("getLastWebPreferences", &WebContents::GetLastWebPreferences)
       .SetMethod("getOwnerBrowserWindow", &WebContents::GetOwnerBrowserWindow)
       .SetMethod("hasServiceWorker", &WebContents::HasServiceWorker)
       .SetMethod("unregisterServiceWorker",

atom/browser/api/atom_api_web_contents.h

@@ -224,6 +224,7 @@ class WebContents : public mate::TrackableObject<WebContents>,
 
   // Returns the web preferences of current WebContents.
   v8::Local<v8::Value> GetWebPreferences(v8::Isolate* isolate);
+  v8::Local<v8::Value> GetLastWebPreferences(v8::Isolate* isolate);
 
   // Returns the owner window.
   v8::Local<v8::Value> GetOwnerBrowserWindow();

atom/browser/web_contents_preferences.cc

@@ -48,6 +48,28 @@ WebContentsPreferences::WebContentsPreferences(
   web_contents->SetUserData(UserDataKey(), base::WrapUnique(this));
 
   instances_.push_back(this);
+
+  // Set WebPreferences defaults onto the JS object
+  SetDefaultBoolIfUndefined("plugins", false);
+  SetDefaultBoolIfUndefined(options::kExperimentalFeatures, false);
+  SetDefaultBoolIfUndefined(options::kExperimentalCanvasFeatures, false);
+  bool node = SetDefaultBoolIfUndefined(options::kNodeIntegration, true);
+  SetDefaultBoolIfUndefined(options::kNodeIntegrationInWorker, false);
+  SetDefaultBoolIfUndefined(options::kWebviewTag, node);
+  SetDefaultBoolIfUndefined("sandbox", false);
+  SetDefaultBoolIfUndefined("nativeWindowOpen", false);
+  SetDefaultBoolIfUndefined(options::kContextIsolation, false);
+  SetDefaultBoolIfUndefined("javascript", true);
+  SetDefaultBoolIfUndefined("images", true);
+  SetDefaultBoolIfUndefined("textAreasAreResizable", true);
+  SetDefaultBoolIfUndefined("webgl", true);
+  SetDefaultBoolIfUndefined("webSecurity", true);
+  SetDefaultBoolIfUndefined("allowRunningInsecureContent", false);
+  #if defined(OS_MACOSX)
+  SetDefaultBoolIfUndefined(options::kScrollBounce, false);
+  #endif
+  SetDefaultBoolIfUndefined("offscreen", false);
+  last_web_preferences_.MergeDictionary(&web_preferences_);
 }
 
 WebContentsPreferences::~WebContentsPreferences() {
@@ -56,6 +78,16 @@ WebContentsPreferences::~WebContentsPreferences() {
       instances_.end());
 }
 
+bool WebContentsPreferences::SetDefaultBoolIfUndefined(const std::string key,
+                                                       bool val) {
+  bool existing;
+  if (!web_preferences_.GetBoolean(key, &existing)) {
+    web_preferences_.SetBoolean(key, val);
+    return val;
+  }
+  return existing;
+}
+
 void WebContentsPreferences::Merge(const base::DictionaryValue& extend) {
   web_preferences_.MergeDictionary(&extend);
 }
@@ -80,6 +112,12 @@ void WebContentsPreferences::AppendExtraCommandLineSwitches(
 
   base::DictionaryValue& web_preferences = self->web_preferences_;
 
+  // We are appending args to a webContents so let's save the current state
+  // of our preferences object so that during the lifetime of the WebContents
+  // we can fetch the options used to initally configure the WebContents
+  self->last_web_preferences_.Clear();
+  self->last_web_preferences_.MergeDictionary(&web_preferences);
+
   bool b;
   // Check if plugins are enabled.
   if (web_preferences.GetBoolean("plugins", &b) && b)

atom/browser/web_contents_preferences.h

@@ -57,10 +57,16 @@ class WebContentsPreferences
 
   // Returns the web preferences.
   base::DictionaryValue* web_preferences() { return &web_preferences_; }
+  base::DictionaryValue* last_web_preferences() {
+    return &last_web_preferences_;
+  }
 
  private:
   friend class content::WebContentsUserData<WebContentsPreferences>;
 
+  // Set preference value to given bool if user did not provide value
+  bool SetDefaultBoolIfUndefined(const std::string key, bool val);
+
   // Get preferences value as integer possibly coercing it from a string
   bool GetInteger(const std::string& attributeName, int* intValue);
 
@@ -68,6 +74,7 @@ class WebContentsPreferences
 
   content::WebContents* web_contents_;
   base::DictionaryValue web_preferences_;
+  base::DictionaryValue last_web_preferences_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsPreferences);
 };