Set the default accept header for main resources in RenderFrame

content/renderer/render_frame_impl.cc

 // Copyright 2013 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_frame_impl.h"
 
 #include <map>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 151 matching lines @@
 using blink::WebVector;
 using blink::WebView;
 using base::Time;
 using base::TimeDelta;
 using webkit_glue::WebURLResponseExtraDataImpl;
 
 namespace content {
 
 namespace {
 
+const char kDefaultAcceptHeader[] =
+    "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/"
+    "*;q=0.8";
+const char kAcceptHeader[] = "Accept";
+
 const size_t kExtraCharsBeforeAndAfterSelection = 100;
 
 typedef std::map<int, RenderFrameImpl*> RoutingIDFrameMap;
 static base::LazyInstance<RoutingIDFrameMap> g_routing_id_frame_map =
     LAZY_INSTANCE_INITIALIZER;
 
 typedef std::map<blink::WebFrame*, RenderFrameImpl*> FrameMap;
 base::LazyInstance<FrameMap> g_frame_map = LAZY_INSTANCE_INITIALIZER;
 
 int64 ExtractPostId(const WebHistoryItem& item) {
@@ skipping 2215 matching lines @@
         old_extra_data->was_after_preconnect_request();
 
     if (!custom_user_agent.isNull()) {
       if (custom_user_agent.isEmpty())
         request.clearHTTPHeaderField("User-Agent");
       else
         request.setHTTPHeaderField("User-Agent", custom_user_agent);
     }
   }
 
+  // Add the default accept header for frame request if it has not been set
+  // already.

[ppi, 2014/06/05 15:10:10]

In which circumstances it will be already set?

[clamy, 2014/06/05 15:22:01]

This function is also called on redirects. If the header has been modified after
the default header has been set (which I think is unlikely, but for example
devtools can write special headers), then on a redirect the modification would
be overwritten.

+  if ((request.targetType() == blink::WebURLRequest::TargetIsMainFrame ||
+       request.targetType() == blink::WebURLRequest::TargetIsSubframe) &&
+      request.httpHeaderField(WebString::fromUTF8(kAcceptHeader)).isEmpty()) {
+    request.setHTTPHeaderField(WebString::fromUTF8(kAcceptHeader),
+                               WebString::fromUTF8(kDefaultAcceptHeader));
+  }
+
   // Attach |should_replace_current_entry| state to requests so that, should
   // this navigation later require a request transfer, all state is preserved
   // when it is re-created in the new process.
   bool should_replace_current_entry = false;
   if (navigation_state->is_content_initiated()) {
     should_replace_current_entry = data_source->replacesCurrentHistoryItem();
   } else {
     // If the navigation is browser-initiated, the NavigationState contains the
     // correct value instead of the WebDataSource.
     //
@@ skipping 1126 matching lines @@
 
 RendererCdmManager* RenderFrameImpl::GetCdmManager() {
   if (!cdm_manager_)
     cdm_manager_ = new RendererCdmManager(this);
   return cdm_manager_;
 }
 
 #endif  // defined(OS_ANDROID)
 
 }  // namespace content