[dom_distiller] Add support for incremental viewer.

components/dom_distiller/core/fake_distiller.cc

Index: components/dom_distiller/core/fake_distiller.cc
diff --git a/components/dom_distiller/core/fake_distiller.cc b/components/dom_distiller/core/fake_distiller.cc
index bb5ef92b37bbb1dc4efd365dcd8fdfd03fa3114f..7bd649e7ce128eeae990c5f51a3ccf439aa19a0b 100644
--- a/components/dom_distiller/core/fake_distiller.cc
+++ b/components/dom_distiller/core/fake_distiller.cc
@@ -7,6 +7,7 @@
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
+#include "content/public/test/test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace dom_distiller {
@@ -17,7 +18,16 @@ MockDistillerFactory::~MockDistillerFactory() {}
 
 FakeDistiller::FakeDistiller(bool execute_callback)
     : execute_callback_(execute_callback),
-      destruction_allowed_(true) {
+      destruction_allowed_(true),
+      runner_(NULL) {
+  EXPECT_CALL(*this, Die()).Times(testing::AnyNumber());
+}
+
+FakeDistiller::FakeDistiller(bool execute_callback,
+                             content::MessageLoopRunner* runner)
+    : execute_callback_(execute_callback),
+      destruction_allowed_(true),
+      runner_(runner) {
   EXPECT_CALL(*this, Die()).Times(testing::AnyNumber());
 }
 
@@ -34,6 +44,11 @@ void FakeDistiller::DistillPage(
   url_ = url;
   article_callback_ = article_callback;
   page_callback_ = page_callback;
+  if (runner_) {
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        runner_->QuitClosure());
+  }
   if (execute_callback_) {
     scoped_ptr<DistilledArticleProto> proto(new DistilledArticleProto);
     proto->add_pages()->set_url(url_.spec());
@@ -49,6 +64,12 @@ void FakeDistiller::RunDistillerCallback(
   PostDistillerCallback(proto.Pass());
 }
 
+void FakeDistiller::RunDistillerUpdateCallback(
+    const ArticleDistillationUpdate& update) {
+  page_callback_.Run(update);
+}
+
+
 void FakeDistiller::PostDistillerCallback(
     scoped_ptr<DistilledArticleProto> proto) {
   base::MessageLoop::current()->PostTask(