Start renderer in ContentViewCoreImpl::EvaluateJavaScript.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index c653c1aa97a2bdc4c4a8bfde380dea1c32121fbf..8ab662d16d9c209a3c529f6365092a421f34bbd0 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -153,6 +153,10 @@ class CONTENT_EXPORT WebContentsImpl
   JavaBridgeDispatcherHostManager* java_bridge_dispatcher_host_manager() const {
     return java_bridge_dispatcher_host_manager_.get();
   }
+
+  // In Android WebView, the RenderView needs created even there is no
+  // navigation entry, so the JavaScript could executed without loading page.
+  bool CreateRenderViewWithoutNavigationEntry(RenderViewHost* render_view_host);

[Charlie Reis, 2013/08/20 22:03:49]

This is not ok to add.  For security reasons, there always needs to be a
SiteInstance and NavigationEntry for a WebContents to have a renderer process. 
(The SiteInstance and NavigationEntry dictate what permissions are granted to
the process, as well as which other pages need to end up in the same process to
ensure they can script each other.)

[Charlie Reis, 2013/08/21 22:06:26]

If we are going to go down this road, we need to be much more explicit.  The
method should be CreateRenderViewForInitialEmptyDocument, and it should clearly
state that this allows Android WebViews to use javascript: URLs that load into
the DOMWindow before the first page load.  We need to be very explicit that this
is not safe to do in any context that a web page could get a reference to the
DOMWindow before the first page load.

Also, this should not take in a RenderViewHost, since it's only safe to do this
with the current RednerViewHost of the WebContents.

 #endif
 
   // Expose the render manager for testing.
@@ -751,6 +755,10 @@ class CONTENT_EXPORT WebContentsImpl
   // Clear all PowerSaveBlockers, leave power_save_blocker_ empty.
   void ClearAllPowerSaveBlockers();
 
+  bool CreateRenderView(RenderViewHost* render_view_host,

[Charlie Reis, 2013/08/20 22:03:49]

Please do not add this.  max_page_id is an extremely difficult concept to get
right and can lead to URL spoofs and renderer crashes if specified incorrectly.

+                        int opener_route_id,
+                        int max_page_id);
+
   // Data for core operation ---------------------------------------------------
 
   // Delegate for notifying our owner about stuff. Not owned by us.