Pass more information by argument to the dom_distiller script.

BUG=None

Review URL: https://codereview.chromium.org/1004223002

Cr-Commit-Position: refs/heads/master@{#320899}

components/dom_distiller/content/distiller_page_web_contents.cc

@@ -71,6 +71,14 @@ DistillerPageWebContents::~DistillerPageWebContents() {
     web_contents_->SetDelegate(NULL);
 }
 
+bool DistillerPageWebContents::StringifyOutput() {
+ return false;
+}
+
+bool DistillerPageWebContents::CreateNewContext() {
+ return true;
+}
+
 void DistillerPageWebContents::DistillPageImpl(const GURL& url,
                                                const std::string& script) {
   DCHECK(browser_context_);

components/dom_distiller/content/distiller_page_web_contents.h

@@ -69,6 +69,8 @@ class DistillerPageWebContents : public DistillerPage,
                    const base::string16& error_description) override;
 
  protected:
+  bool StringifyOutput() override;
+  bool CreateNewContext() override;
   void DistillPageImpl(const GURL& url, const std::string& script) override;
 
  private:

components/dom_distiller/core/distiller_page.cc

@@ -23,9 +23,13 @@ namespace dom_distiller {
 namespace {
 
 const char* kOptionsPlaceholder = "$$OPTIONS";
+const char* kStringifyPlaceholder = "$$STRINGIFY";
+const char* kNewContextPlaceholder = "$$NEW_CONTEXT";
 
 std::string GetDistillerScriptWithOptions(
-    const dom_distiller::proto::DomDistillerOptions& options) {
+    const dom_distiller::proto::DomDistillerOptions& options,
+    bool stringify_output,
+    bool create_new_context) {
   std::string script = ResourceBundle::GetSharedInstance()
                            .GetRawDataResource(IDR_DISTILLER_JS)
                            .as_string();
@@ -45,6 +49,25 @@ std::string GetDistillerScriptWithOptions(
             script.find(kOptionsPlaceholder, options_offset + 1));
   script =
       script.replace(options_offset, strlen(kOptionsPlaceholder), options_json);
+
+  std::string stringify = stringify_output ? "true" : "false";
+  size_t stringify_offset = script.find(kStringifyPlaceholder);
+  DCHECK_NE(std::string::npos, stringify_offset);
+  DCHECK_EQ(std::string::npos,
+            script.find(kStringifyPlaceholder, stringify_offset + 1));
+  script = script.replace(stringify_offset,
+                          strlen(kStringifyPlaceholder),
+                          stringify);
+
+  std::string new_context = create_new_context ? "true" : "false";
+  size_t new_context_offset = script.find(kNewContextPlaceholder);
+  DCHECK_NE(std::string::npos, new_context_offset);
+  DCHECK_EQ(std::string::npos,
+            script.find(kNewContextPlaceholder, new_context_offset + 1));
+  script = script.replace(new_context_offset,
+                          strlen(kNewContextPlaceholder),
+                          new_context);
+
   return script;
 }
 
@@ -65,7 +88,9 @@ void DistillerPage::DistillPage(
   // the callback to OnDistillationDone happens.
   ready_ = false;
   distiller_page_callback_ = callback;
-  DistillPageImpl(gurl, GetDistillerScriptWithOptions(options));
+  DistillPageImpl(gurl, GetDistillerScriptWithOptions(options,
+                                                      StringifyOutput(),
+                                                      CreateNewContext()));
 }
 
 void DistillerPage::OnDistillationDone(const GURL& page_url,

components/dom_distiller/core/distiller_page.h

@@ -55,6 +55,14 @@ class DistillerPage {
   // should be the same regardless of the DistillerPage implementation.
   virtual void DistillPageImpl(const GURL& url, const std::string& script) = 0;
 
+  // The value returned between the JavaScript and the DistillerPage can be
+  // either a dictionary with all the content, or a stringified version.
+  virtual bool StringifyOutput() = 0;
+
+  // If true, forces the creation of a new window context to evaluate the
+  // JavaScript.
+  virtual bool CreateNewContext() = 0;
+
  private:
   bool ready_;
   DistillerPageCallback distiller_page_callback_;

components/dom_distiller/core/fake_distiller_page.h

@@ -30,6 +30,8 @@ class MockDistillerPage : public DistillerPage {
  public:
   MockDistillerPage();
   virtual ~MockDistillerPage();
+  bool StringifyOutput() override { return false; };
+  bool CreateNewContext() override { return false; };
   MOCK_METHOD2(DistillPageImpl,
                void(const GURL& gurl, const std::string& script));
 };

components/dom_distiller/core/javascript/domdistiller.js

@@ -4,7 +4,7 @@
 
 // Applies DomDistillerJs to the content of the page and returns a
 // DomDistillerResults (as a javascript object/dict).
-(function() {
+(function(options, stringify_output, use_new_context) {
   try {
     // The generated domdistiller.js accesses the window object only explicitly
     // via the window name. So, we create a new object with the normal window
@@ -14,16 +14,7 @@
       // This include will be processed at build time by grit.
       <include src="../../../../third_party/dom_distiller_js/package/js/domdistiller.js"/>
     }
-    <if expr="is_ios">
-      // UIWebView's JavaScript engine has a bug that causes crashes when
-      // creating a separate window object, so allow the script to run directly
-      // in the window until a better solution is created.
-      // TODO(kkhorimoto): investigate whether this is necessary for WKWebView.
-      var context = window;
-    </if>
-    <if expr="not is_ios">
-      var context = Object.create(window);
-    </if>
+    var context = use_new_context ? Object.create(window) : window
     context.setTimeout = function() {};
     context.clearTimeout = function() {};
     initialize(context);
@@ -31,17 +22,17 @@
     // The OPTIONS placeholder will be replaced with the DomDistillerOptions at
     // runtime.
     var distiller = context.org.chromium.distiller.DomDistiller;
-    var res = distiller.applyWithOptions($$OPTIONS);
-  <if expr="is_ios">
-    // UIWebView requires javascript to return a single string value.
-    return JSON.stringify(res);
-  </if>
-  <if expr="not is_ios">
+    var res = distiller.applyWithOptions(options);
+
+    if (stringify_output) {
+      return JSON.stringify(res);
+    }
     return res;
-  </if>
   } catch (e) {
     window.console.error("Error during distillation: " + e);
     if (e.stack != undefined) window.console.error(e.stack);
   }
   return undefined;
-})()
+})(options = $$OPTIONS,
+   stringify_output = $$STRINGIFY,
+   use_new_context = $$NEW_CONTEXT)

components/dom_distiller/ios/distiller_page_ios.h

@@ -33,12 +33,14 @@ class DistillerPageIOS : public DistillerPage {
   explicit DistillerPageIOS(web::BrowserState* browser_state);
   ~DistillerPageIOS() override;
 
+ protected:
+  bool StringifyOutput() override;
+  bool CreateNewContext() override;
+  void DistillPageImpl(const GURL& url, const std::string& script) override;
+
  private:
   friend class DistillerWebStateObserver;
 
-  // DistillerPage implementation:
-  void DistillPageImpl(const GURL& url, const std::string& script) override;
-
   // Called by |web_state_observer_| once the page has finished loading.
   void OnLoadURLDone(web::PageLoadCompletionStatus load_completion_status);
 

components/dom_distiller/ios/distiller_page_ios.mm

@@ -51,6 +51,19 @@ DistillerPageIOS::DistillerPageIOS(web::BrowserState* browser_state)
 DistillerPageIOS::~DistillerPageIOS() {
 }
 
+bool DistillerPageIOS::StringifyOutput() {
+ // UIWebView requires JavaScript to return a single string value.
+ return true;
+}
+
+bool DistillerPageIOS::CreateNewContext() {
+  // UIWebView's JavaScript engine has a bug that causes crashes when
+  // creating a separate window object, so allow the script to run directly
+  // in the window until a better solution is created.
+  // TODO(kkhorimoto): investigate whether this is necessary for WKWebView.
+ return false;
+}
+
 void DistillerPageIOS::DistillPageImpl(const GURL& url,
                                        const std::string& script) {
   if (!url.is_valid() || !script.length())