Transfer user agent override info between browser and renderer

content/renderer/render_view_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
@@ skipping 1430 matching lines @@
           original_request.httpHeaderField(WebString::fromUTF8("Referer"))),
           GetReferrerPolicyFromRequest(frame, original_request));
     }
 
     string16 method = request.httpMethod();
     if (EqualsASCII(method, "POST")) {
       params.is_post = true;
       params.post_id = ExtractPostId(item);
     }
 
+    // Send the user agent override back.
+    params.is_overriding_user_agent =
+        document_state->is_overriding_user_agent();
+
     // Save some histogram data so we can compute the average memory used per
     // page load of the glyphs.
     UMA_HISTOGRAM_COUNTS_10000("Memory.GlyphPagesPerLoad",
                                webkit_glue::GetGlyphPageCount());
 
     // This message needs to be sent before any of allowScripts(),
     // allowImages(), allowPlugins() is called for the new page, so that when
     // these functions send a ViewHostMsg_ContentBlocked message, it arrives
     // after the ViewHostMsg_FrameNavigate message.
     Send(new ViewHostMsg_FrameNavigate(routing_id_, params));
@@ skipping 1272 matching lines @@
   bool content_initiated = !pending_navigation_params_.get();
 
   DocumentState* document_state = DocumentState::FromDataSource(ds);
   if (!document_state) {
     document_state = new DocumentState;
     ds->setExtraData(document_state);
     if (!content_initiated)
       PopulateDocumentStateFromPending(document_state);
   }
 
+  // Carry over the user agent override flag, if it exists.
+  if (content_initiated && webview() && webview()->mainFrame() &&
+      webview()->mainFrame()->dataSource()) {

[darin (slow to review), 2012/06/19 18:36:34]

why do you need to null-check mainFrame()->dataSource()?  are you sure that is
necessary?  below, i see code that dereferences old_frame->dataSource() without
null checking it first.

[gone, 2012/06/19 21:44:22]

Oddly, yes.  At least in my Android build, I get it rather frequently.  I don't
recall seeing it happen for data source below, though.  Maybe it can be null if
there's no referrer?

+    DocumentState* old_document_state =
+        DocumentState::FromDataSource(webview()->mainFrame()->dataSource());
+    if (old_document_state) {
+      document_state->set_is_overriding_user_agent(
+          old_document_state->is_overriding_user_agent());
+    }
+  }
+
   // The rest of RenderView assumes that a WebDataSource will always have a
   // non-null NavigationState.
   if (content_initiated)
     document_state->set_navigation_state(
         NavigationState::CreateContentInitiated());
   else {
     document_state->set_navigation_state(CreateNavigationStateFromPending());
     pending_navigation_params_.reset();
   }
 
@@ skipping 63 matching lines @@
   }
 
   if (IsReload(params))
     document_state->set_load_type(DocumentState::RELOAD);
   else if (!params.state.empty())
     document_state->set_load_type(DocumentState::HISTORY_LOAD);
   else
     document_state->set_load_type(DocumentState::NORMAL_LOAD);
 
   document_state->set_referrer_policy(params.referrer.policy);
+  document_state->set_is_overriding_user_agent(params.is_overriding_user_agent);
 }
 
 NavigationState* RenderViewImpl::CreateNavigationStateFromPending() {
   const ViewMsg_Navigate_Params& params = *pending_navigation_params_.get();
   NavigationState* navigation_state = NULL;
 
   // A navigation resulting from loading a javascript URL should not be treated
   // as a browser initiated event.  Instead, we want it to look as if the page
   // initiated any load resulting from JS execution.
   if (!params.url.SchemeIs(chrome::kJavaScriptScheme)) {
@@ skipping 856 matching lines @@
 
   Send(new ViewHostMsg_RouteMessageEvent(routing_id_, params));
   return true;
 }
 
 void RenderViewImpl::willOpenSocketStream(
     WebSocketStreamHandle* handle) {
   SocketStreamHandleData::AddToHandle(handle, routing_id_);
 }
 
+WebKit::WebString RenderViewImpl::userAgentOverride(
+    WebKit::WebFrame* frame,
+    const WebKit::WebURL& url) {
+  if (webview() && webview()->mainFrame() &&

[darin (slow to review), 2012/06/19 18:36:34]

nit: return early to minimize indentation for the bulk of the function

[gone, 2012/06/19 21:44:22]

Done.

+      !renderer_preferences_.user_agent_override.empty()) {
+    WebFrame* main_frame = webview()->mainFrame();
+    WebDataSource* data_source = NULL;
+
+    // If we're in the middle of committing a load, the data source we need
+    // will still be provisional.
+    if (main_frame->provisionalDataSource()) {
+      data_source = main_frame->provisionalDataSource();
+    } else {
+      data_source = main_frame->dataSource();
+    }
+
+    DocumentState* document_state =
+        data_source ? DocumentState::FromDataSource(data_source) : NULL;
+    if (document_state && document_state->is_overriding_user_agent()) {
+      return WebString::fromUTF8(renderer_preferences_.user_agent_override);
+    }
+  }
+
+  return WebKit::WebString();
+}
+
 // WebKit::WebPageSerializerClient implementation ------------------------------
 
 void RenderViewImpl::didSerializeDataForFrame(
     const WebURL& frame_url,
     const WebCString& data,
     WebPageSerializerClient::PageSerializationStatus status) {
   Send(new ViewHostMsg_SendSerializedHtmlData(
     routing_id(),
     frame_url,
     data.data(),
@@ skipping 1915 matching lines @@
 bool RenderViewImpl::WebWidgetHandlesCompositorScheduling() const {
   return !!RenderThreadImpl::current()->compositor_thread();
 }
 
 void RenderViewImpl::OnJavaBridgeInit() {
   DCHECK(!java_bridge_dispatcher_);
 #if defined(ENABLE_JAVA_BRIDGE)
   java_bridge_dispatcher_ = new JavaBridgeDispatcher(this);
 #endif
 }