mandoline: Add back/forward support and UI.

components/web_view/web_view_impl.cc

Index: components/web_view/web_view_impl.cc
diff --git a/components/web_view/web_view_impl.cc b/components/web_view/web_view_impl.cc
index e73058937ec679c22701d31446d6c1c148c9083c..d355a9e1ab74715f293e135f2524389907595ccb 100644
--- a/components/web_view/web_view_impl.cc
+++ b/components/web_view/web_view_impl.cc
@@ -13,6 +13,7 @@
 #include "components/web_view/frame_connection.h"
 #include "components/web_view/frame_devtools_agent.h"
 #include "components/web_view/frame_tree.h"
+#include "components/web_view/navigation_entry.h"
 #include "components/web_view/pending_web_view_load.h"
 #include "mojo/application/public/cpp/application_impl.h"
 #include "mojo/converters/geometry/geometry_type_converters.h"
@@ -75,12 +76,27 @@ void WebViewImpl::OnLoad() {
   content_->Embed(view_tree_client.Pass());
 }
 
+void WebViewImpl::UpdateBackForwardEnableState() {
+  client_->BackForwardChanged(back_list_.size() > 0, forward_list_.size() > 0);

[msw, 2015/09/04 22:05:00]

nit: use !empty?

+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // WebViewImpl, WebView implementation:
 
 void WebViewImpl::LoadRequest(mojo::URLRequestPtr request) {
+  if (current_page_request_) {
+    // TODO(erg): This doesn't deal with redirect chains. If you navigate to a
+    // site, and it 300s, we put both the url which caused the 300 and the
+    // target url here, when we should not add the redirect url to the back
+    // list.
+    back_list_.push_back(current_page_request_.Pass());
+  }
+  UpdateBackForwardEnableState();
+
+  current_page_request_.reset(new NavigationEntry(request.Pass()));
+
   pending_load_.reset(new PendingWebViewLoad(this));
-  pending_load_->Init(request.Pass());
+  pending_load_->Init(current_page_request_->AsURLRequest());
 }
 
 void WebViewImpl::GetViewTreeClient(
@@ -88,6 +104,33 @@ void WebViewImpl::GetViewTreeClient(
   mojo::ViewTreeConnection::Create(this, view_tree_client.Pass());
 }
 
+void WebViewImpl::GoBack() {
+  if (back_list_.size() == 0)

[msw, 2015/09/04 22:05:00]

nit: empty

+    return;
+
+  // Take the current page request and put it in the forward list.
+  forward_list_.push_back(current_page_request_.Pass());
+
+  mojo::URLRequestPtr new_request = back_list_.back()->AsURLRequest();
+  back_list_.resize(back_list_.size() - 1);
+
+  UpdateBackForwardEnableState();
+  client_->TopLevelNavigate(new_request.Pass());
+}
+
+void WebViewImpl::GoForward() {
+  if (forward_list_.size() == 0)

[msw, 2015/09/04 22:05:00]

nit: empty

+    return;
+
+  back_list_.push_back(current_page_request_.Pass());
+
+  mojo::URLRequestPtr new_request = forward_list_.back()->AsURLRequest();
+  forward_list_.resize(forward_list_.size() - 1);
+
+  UpdateBackForwardEnableState();
+  client_->TopLevelNavigate(new_request.Pass());
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // WebViewImpl, mojo::ViewTreeDelegate implementation: