Create distiller files for Reading List.

components/dom_distiller/ios/distiller_page_ios.mm

Index: components/dom_distiller/ios/distiller_page_ios.mm
diff --git a/components/dom_distiller/ios/distiller_page_ios.mm b/components/dom_distiller/ios/distiller_page_ios.mm
index 8ffacdfcbddcedc8bdfd58374cbbabd3db14747e..e54ff2481dbcb83beb2fe6bff8835516ab62d8c1 100644
--- a/components/dom_distiller/ios/distiller_page_ios.mm
+++ b/components/dom_distiller/ios/distiller_page_ios.mm
@@ -8,12 +8,14 @@
 
 #include <utility>
 
+#include "base/bind.h"
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "base/values.h"
 #include "components/favicon/ios/web_favicon_driver.h"
 #include "ios/web/public/browser_state.h"
@@ -134,17 +136,33 @@ void DistillerWebStateObserver::WebStateDestroyed() {
 
 #pragma mark -
 
-DistillerPageIOS::DistillerPageIOS(
-    FaviconWebStateDispatcher* web_state_dispatcher)
-    : web_state_dispatcher_(web_state_dispatcher), weak_ptr_factory_(this) {}
-
-DistillerPageIOS::~DistillerPageIOS() {
+DistillerPageIOS::DistillerPageIOS(std::unique_ptr<web::WebState> web_state)
+    : web_state_(std::move(web_state)), weak_ptr_factory_(this) {
+  if (web_state_) {
+    web_state_observer_ =
+        base::MakeUnique<DistillerWebStateObserver>(web_state_.get(), this);
+  }
 }
 
 bool DistillerPageIOS::StringifyOutput() {
   return false;
 }
 
+DistillerPageIOS::~DistillerPageIOS() {}
+
+std::unique_ptr<web::WebState> DistillerPageIOS::ReplaceWebState(

[gambard, 2016/12/27 09:35:58]

I am not fond of this logic of switching web states around.
Instead, can't you use a lazy getter?
The subclass would only need to destroy the WebState and override the getter.
WDYT?

[Olivier, 2016/12/27 10:08:36]

We need to update the observer. I am not sure how to do it with a simple getter.

+    std::unique_ptr<web::WebState> web_state) {
+  std::unique_ptr<web::WebState> old_web_state = std::move(web_state_);
+  web_state_ = std::move(web_state);
+  if (web_state_) {
+    web_state_observer_ =
+        base::MakeUnique<DistillerWebStateObserver>(web_state_.get(), this);
+  } else {
+    web_state_observer_.reset();
+  }
+  return old_web_state;
+}
+
 void DistillerPageIOS::DistillPageImpl(const GURL& url,
                                        const std::string& script) {
   if (!url.is_valid() || !script.length())
@@ -152,21 +170,10 @@ void DistillerPageIOS::DistillPageImpl(const GURL& url,
   url_ = url;
   script_ = script;
 
-  web_state_ = web_state_dispatcher_->RequestWebState();
-
   if (!web_state_) {
     OnLoadURLDone(web::PageLoadCompletionStatus::FAILURE);
     return;
   }
-
-  web_state_observer_ =
-      base::MakeUnique<DistillerWebStateObserver>(web_state_, this);
-
-  // The favicon driver needs to know which URL is currently fetched.
-  favicon::WebFaviconDriver* favicon_driver =
-      favicon::WebFaviconDriver::FromWebState(web_state_);
-  favicon_driver->FetchFavicon(url_);

[gambard, 2016/12/27 09:35:58]

I don't see this code in the new version.

[Olivier, 2016/12/27 10:08:36]

Done.

-
   // Load page using WebState.
   web::NavigationManager::WebLoadParams params(url_);
   web_state_->SetWebUsageEnabled(true);
@@ -185,10 +192,13 @@ void DistillerPageIOS::OnLoadURLDone(
     HandleJavaScriptResult(nil);
     return;
   }
-
-  // Inject the script.
   base::WeakPtr<DistillerPageIOS> weak_this = weak_ptr_factory_.GetWeakPtr();
-
+  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE, base::Bind(&DistillerPageIOS::DistillPage, weak_this),
+      base::TimeDelta::FromSeconds(2));

[gambard, 2016/12/27 09:35:58]

Use a constant for the "2".

[Olivier, 2016/12/27 10:08:36]

Code removed.

+}
+void DistillerPageIOS::DistillPage() {
+  base::WeakPtr<DistillerPageIOS> weak_this = weak_ptr_factory_.GetWeakPtr();
   [[web_state_->GetJSInjectionReceiver()
       instanceOfClass:[CRWJSInjectionManager class]]
       executeJavaScript:base::SysUTF8ToNSString(script_)
@@ -200,8 +210,6 @@ void DistillerPageIOS::OnLoadURLDone(
 }
 
 void DistillerPageIOS::HandleJavaScriptResult(id result) {
-  web_state_dispatcher_->ReturnWebState(web_state_);
-  web_state_ = nullptr;
   std::unique_ptr<base::Value> resultValue = base::Value::CreateNullValue();
   if (result) {
     resultValue = ValueResultFromScriptResult(result);