aw: Fix race between first frame draw and view detach causing deadlock.

android_webview/browser/browser_view_renderer.h

Index: android_webview/browser/browser_view_renderer.h
diff --git a/android_webview/browser/browser_view_renderer.h b/android_webview/browser/browser_view_renderer.h
index 7882f8097c7fd3ff55055c0f557b187399bf3033..24e22781e9dc79405df4f70509a05180ce235f28 100644
--- a/android_webview/browser/browser_view_renderer.h
+++ b/android_webview/browser/browser_view_renderer.h
@@ -204,7 +204,11 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient,
   bool offscreen_pre_raster_;
 
   // Must do a synchronous draw first to ensure GL bindings are initialized.
-  // TODO(boliu): Wait on render thread and remove this.
+  // TODO(boliu): Wait on render thread and remove this. When the
+  // first synchronous draw requirement is removed,
+  // RenderThreadManager::DeleteHardwareRendererOnUI will need to
+  // change, because it will no longer be true that having received a
+  // frame means that GL bindings have been initialized.
   bool allow_async_draw_;
 
   gfx::Vector2d last_on_draw_scroll_offset_;