Adds a way to determine id of content handler that created app

components/pdf_viewer/pdf_viewer.cc

 // Copyright 2015 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 "base/bind.h"
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/view_manager/public/cpp/types.h"
 #include "components/view_manager/public/cpp/view.h"
@@ skipping 35 matching lines @@
 const uint32_t g_background_color = 0xFF888888;
 const uint32_t g_transparent_color = 0x00000000;
 
 namespace pdf_viewer {
 namespace {
 
 void LostContext(void*) {
   DCHECK(false);
 }
 
+void OnGotContentHandlerID(uint32_t content_handler_id) {}
+
 // BitmapUploader is useful if you want to draw a bitmap or color in a View.
 class BitmapUploader : public mojo::SurfaceClient {
  public:
   explicit BitmapUploader(mojo::View* view)
       : view_(view),
         color_(g_transparent_color),
         width_(0),
         height_(0),
         format_(BGRA),
         next_resource_id_(1u),
         id_namespace_(0u),
         local_id_(0u),
         returner_binding_(this) {
   }
   ~BitmapUploader() override {
     MojoGLES2DestroyContext(gles2_context_);
   }
 
   void Init(mojo::Shell* shell) {
     surface_ = view_->RequestSurface();
 
     mojo::ServiceProviderPtr gpu_service_provider;
     mojo::URLRequestPtr request2(mojo::URLRequest::New());
     request2->url = mojo::String::From("mojo:view_manager");
     shell->ConnectToApplication(request2.Pass(),
                                 mojo::GetProxy(&gpu_service_provider), nullptr,
-                                nullptr);
+                                nullptr, base::Bind(&OnGotContentHandlerID));
     ConnectToService(gpu_service_provider.get(), &gpu_service_);
 
     mojo::CommandBufferPtr gles2_client;
     gpu_service_->CreateOffscreenGLES2Context(GetProxy(&gles2_client));
     gles2_context_ = MojoGLES2CreateContext(
         gles2_client.PassInterface().PassHandle().release().value(),
         &LostContext, NULL, mojo::Environment::GetDefaultAsyncWaiter());
     MojoGLES2MakeCurrent(gles2_context_);
   }
 
@@ skipping 412 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(PDFViewer);
 };
 
 }  // namespace
 }  // namespace pdf_viewer
 
 MojoResult MojoMain(MojoHandle application_request) {
   mojo::ApplicationRunner runner(new pdf_viewer::PDFViewer());
   return runner.Run(application_request);
 }