Refactor getInstalledRelatedApps code and add manifest logic and tests.

content/renderer/render_frame_impl.h

Index: content/renderer/render_frame_impl.h
diff --git a/content/renderer/render_frame_impl.h b/content/renderer/render_frame_impl.h
index cc28f1f41ab015f8dbed479de9a5fb226d4e22dc..7e0ac6ccf581415c408342fbca4079e5e3cfb5a6 100644
--- a/content/renderer/render_frame_impl.h
+++ b/content/renderer/render_frame_impl.h
@@ -94,6 +94,7 @@ struct WebCompositionUnderline;
 struct WebContextMenuData;
 struct WebCursorInfo;
 struct WebFindOptions;
+class WebRelatedAppsFetcher;
 }  // namespace blink
 
 namespace gfx {
@@ -144,6 +145,7 @@ class NavigationState;
 class PepperPluginInstanceImpl;
 class PresentationDispatcher;
 class PushMessagingDispatcher;
+class RelatedAppsFetcher;
 class RenderAccessibilityImpl;
 class RendererMediaPlayerManager;
 class RendererPpapiHost;
@@ -636,6 +638,7 @@ class CONTENT_EXPORT RenderFrameImpl
                            blink::WebStorageQuotaCallbacks callbacks) override;
   blink::WebPushClient* pushClient() override;
   blink::WebPresentationClient* presentationClient() override;
+  blink::WebRelatedAppsFetcher* relatedAppsFetcher() override;
   void willStartUsingPeerConnectionHandler(
       blink::WebRTCPeerConnectionHandler* handler) override;
   blink::WebUserMediaClient* userMediaClient() override;
@@ -1306,6 +1309,8 @@ class CONTENT_EXPORT RenderFrameImpl
   // AccessibilityModeOff.
   RenderAccessibilityImpl* render_accessibility_;
 
+  std::unique_ptr<RelatedAppsFetcher> related_apps_fetcher_;
+
   // Manages play, pause notifications for WebMediaPlayer implementations; its
   // lifetime is tied to the RenderFrame via the RenderFrameObserver interface.
   media::RendererWebMediaPlayerDelegate* media_player_delegate_;