Transfer user agent info between browser and renderer

Upstreaming "Request desktop site" feature from Android. Previous CLs:
* http://codereview.chromium.org/9999010/
  Stores the original request URL in NavigationEntry
* http://codereview.chromium.org/10170016/
  Adds info about user agent overrides to WebContents and NavigationEntries
* https://bugs.webkit.org/show_bug.cgi?id=83959
  Adds ability to override the user agent string per-WebFrameClient

The previous CLs added the framework to the browser and renderer to support
overriding the default user agent with a different string. This CL connects the 
two sides, letting the browser pass information about the user agent override the 
renderer should be using for a given navigation.

There's a slightly out of date doc at http://go/chrome_android_rds that's being
adjusted as CLs land.

Changes from previous CLs:
* The user agent override string is now stored in the RendererPreferences instead
  of directly inside the RenderViewImpl and WebContentsImpl.

* Setting the user agent override for a WebContents forces a reload if a page is
  currently being loaded to avoid giving different parts of a web page different
  user agents.

Additions:
* The browser-side lets the renderer know about the user agent override string
  through an IPC call that occurs when the user agent is set in WebContentsImpl
  and when a RenderViewImpl is created.

* Instant + Prefetch classes have been adjusted to set carry over the override flags
  from the WebContents they're being used for.

* A new function is added to the NavigationController to allow setting the override
  flag for a particular NavigationEntry before it is loaded.

* The NavigationController is alerted to new navigations by the renderer with an IPC 
  call and saves the override state in the relevant NavigationEntry.

* DocumentState stores whether the user agent override was used for a given navigation,
  and is set in RenderViewImpl::didCreateDataSource().  Both browser- and 
  renderer-initiated navigations go through here, with
  browser-initiated navigations using a ViewMsg_Navigate_Params.

* WebFrameClient::userAgentOverride() is overridden by RenderViewImpl to return the 
  user agent for the current main frame.  If the main frame is provisionally loading
  something, we use the override for the provisional load instead.

Internal bugs=6272286,6213026
BUG=112923
TEST=


Review URL: https://chromiumcodereview.appspot.com/10450002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@143279 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 7 insertions, 0 deletions

diff --git a/content/browser/web_contents/navigation_controller_impl.h b/content/browser/web_contents/navigation_controller_impl.h
index dfe4dd6..5053475 100644
--- a/content/browser/web_contents/navigation_controller_impl.h
+++ b/content/browser/web_contents/navigation_controller_impl.h
@@ -63,6 +63,13 @@ class CONTENT_EXPORT NavigationControllerImpl
                                    const content::Referrer& referrer,
                                    content::PageTransition type,
                                    const std::string& extra_headers) OVERRIDE;
+  virtual void LoadURLWithUserAgentOverride(
+      const GURL& url,
+      const content::Referrer& referrer,
+      content::PageTransition type,
+      bool is_renderer_initiated,
+      const std::string& extra_headers,
+      bool is_overriding_user_agent) OVERRIDE;
   virtual void TransferURL(
       const GURL& url,
       const content::Referrer& referrer,