Add calls to the server to request WebAPK updates.

chrome/browser/android/webapk/webapk_installer.cc

Index: chrome/browser/android/webapk/webapk_installer.cc
diff --git a/chrome/browser/android/webapk/webapk_installer.cc b/chrome/browser/android/webapk/webapk_installer.cc
index 5acb396200b16497b01c67f7013a7d2722cc105c..e33cc1e87addaffd30aa58265092ec0b59c7856f 100644
--- a/chrome/browser/android/webapk/webapk_installer.cc
+++ b/chrome/browser/android/webapk/webapk_installer.cc
@@ -89,6 +89,14 @@ WebApkInstaller::WebApkInstaller(content::BrowserContext* browser_context,
                : kDefaultWebApkServerUrl);
 }
 
+WebApkInstaller::WebApkInstaller(content::BrowserContext* browser_context,
+                                 const ShortcutInfo& shortcut_info,
+                                 const SkBitmap& shortcut_icon,
+                                 const std::string& webapk_package)
+    : WebApkInstaller(browser_context, shortcut_info, shortcut_icon) {
+   webapk_package_ = webapk_package;
+}
+
 WebApkInstaller::~WebApkInstaller() {}
 
 // static
@@ -101,11 +109,25 @@ void WebApkInstaller::InstallAsync(const FinishCallback& finish_callback) {
   finish_callback_ = finish_callback;
   // base::Unretained() is safe because WebApkInstaller owns itself and does not
   // start the timeout timer till after
-  // InitializeRequestContextGetterOnUIThread() is called.
+  // InitializeCreateRequestContextGetterOnUIThread() is called.

[pkotwicz, 2016/08/03 01:07:06]

I think you can use BrowserThread::PostTaskAndReply() so that you do not need to
have both   WebApkInstaller::InitializeCreateRequestContextGetterOnUIThread()
and WebApkInstaller::InitializeUpdateRequestContextGetterOnUIThread()

[Xi Han, 2016/08/03 17:30:05]

Good idea, thanks!

   content::BrowserThread::PostTask(
       content::BrowserThread::UI, FROM_HERE,
-      base::Bind(&WebApkInstaller::InitializeRequestContextGetterOnUIThread,
-                 base::Unretained(this)));
+      base::Bind(
+          &WebApkInstaller::InitializeCreateRequestContextGetterOnUIThread,
+          base::Unretained(this)));
+}
+
+void WebApkInstaller::UpdateAsync(const FinishCallback& finish_callback) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  finish_callback_ = finish_callback;
+  // base::Unretained() is safe because WebApkInstaller owns itself and does not
+  // start the timeout timer till after
+  // InitializeUpdateRequestContextGetterOnUIThread() is called.
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI, FROM_HERE,
+      base::Bind(
+          &WebApkInstaller::InitializeUpdateRequestContextGetterOnUIThread,
+          base::Unretained(this)));
 }
 
 void WebApkInstaller::OnURLFetchComplete(const net::URLFetcher* source) {
@@ -121,23 +143,23 @@ void WebApkInstaller::OnURLFetchComplete(const net::URLFetcher* source) {
   std::string response_string;
   source->GetResponseAsString(&response_string);
 
-  std::unique_ptr<webapk::CreateWebApkResponse> response(
-      new webapk::CreateWebApkResponse);
+  std::unique_ptr<webapk::WebApkResponse> response(
+      new webapk::WebApkResponse);
   if (!response->ParseFromString(response_string)) {
     OnFailure();
     return;
   }
 
-  if (response->signed_download_url().empty() ||
+  if (response->signed_market_url().empty() ||
       response->webapk_package_name().empty()) {
     OnFailure();
     return;
   }
-  OnGotWebApkDownloadUrl(response->signed_download_url(),
+  OnGotWebApkDownloadUrl(response->signed_market_url(),
                          response->webapk_package_name());
 }
 
-void WebApkInstaller::InitializeRequestContextGetterOnUIThread() {
+void WebApkInstaller::InitializeCreateRequestContextGetterOnUIThread() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   // Must be called on UI thread.
   request_context_getter_ =
@@ -149,11 +171,37 @@ void WebApkInstaller::InitializeRequestContextGetterOnUIThread() {
                  io_weak_ptr_factory_.GetWeakPtr()));
 }
 
+void WebApkInstaller::InitializeUpdateRequestContextGetterOnUIThread() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  // Must be called on UI thread.
+  request_context_getter_ =
+      Profile::FromBrowserContext(browser_context_)->GetRequestContext();
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&WebApkInstaller::SendUpdateWebApkRequest,
+                 base::Unretained(this)));
+}
+
 void WebApkInstaller::SendCreateWebApkRequest() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-  std::unique_ptr<webapk::CreateWebApkRequest> request =
-      BuildCreateWebApkRequest();
+  SendRequest(BuildRequest(std::unique_ptr<webapk::CreateWebApkRequest>(
+      new webapk::CreateWebApkRequest)));
+}
+
+void WebApkInstaller::SendUpdateWebApkRequest() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
+  std::unique_ptr<webapk::UpdateWebApkRequest> request
+      = BuildRequest(std::unique_ptr<webapk::UpdateWebApkRequest>(
+          new webapk::UpdateWebApkRequest));
+  webapk::WebApk* webapk = request->mutable_webapk();
+  webapk->set_package_name(webapk_package_);
+  SendRequest(std::move(request));
+}
+
+template <class RequestProto>
+void WebApkInstaller::SendRequest(std::unique_ptr<RequestProto> request_proto) {

[pkotwicz, 2016/08/03 01:07:06]

Nit: You can change the type to std::unique_ptr<::google::protobuf::MessageLite>

[Xi Han, 2016/08/03 17:30:05]

It is great to have the super class of the proto, so we don't need the template
at all.

   timer_.Start(FROM_HERE,
                base::TimeDelta::FromMilliseconds(kWebApkDownloadUrlTimeoutMs),
                base::Bind(&WebApkInstaller::OnTimeout,
@@ -163,7 +211,7 @@ void WebApkInstaller::SendCreateWebApkRequest() {
       net::URLFetcher::Create(server_url_, net::URLFetcher::POST, this);
   url_fetcher_->SetRequestContext(request_context_getter_);
   std::string serialized_request;
-  request->SerializeToString(&serialized_request);
+  request_proto->SerializeToString(&serialized_request);
   url_fetcher_->SetUploadData(kProtoMimeType, serialized_request);
   url_fetcher_->Start();
 }
@@ -215,11 +263,9 @@ void WebApkInstaller::OnWebApkDownloaded(const base::FilePath& file_path,
     OnFailure();
 }
 

[pkotwicz, 2016/08/03 01:07:06]

I think that templates are generally discouraged in Chromium (though I can't
find a place in the style guide which says this)

Here are my suggestions:
Change function to
std::unique_ptr<webapk::WebApk> WebApkInstaller::BuildWebApkProto() {}
and use CreateWebApkRequest::set_allocated_webapk()

OR

Change function to 
void WebApkInstaller::PopulateWebApkProto(webapk::WebApk* webapk) {}

The generated C++ code for the proto is located in
out/gn_Debug/gen/chrome/browser/android/webapk/webapk.pb.h

[Xi Han, 2016/08/03 17:30:05]

Ok, I refereed some examples of the template in Chromium, so I don't know
template isn't encouraged in Chromium code base.
The void WebApkInstaller::PopulateWebApkProto(webapk::WebApk* webapk) sounds
good to me. Adopt this and remove the template.

-std::unique_ptr<webapk::CreateWebApkRequest>
-WebApkInstaller::BuildCreateWebApkRequest() {
-  std::unique_ptr<webapk::CreateWebApkRequest> request(
-      new webapk::CreateWebApkRequest);
-
+template<class RequestProto>
+std::unique_ptr<RequestProto> WebApkInstaller::BuildRequest(
+    std::unique_ptr<RequestProto> request) {
   webapk::WebApk* webapk = request->mutable_webapk();
   webapk->set_manifest_url(shortcut_info_.manifest_url.spec());
   webapk->set_requester_application_package(
@@ -260,11 +306,11 @@ void WebApkInstaller::OnTimeout() {
 }
 
 void WebApkInstaller::OnSuccess() {
-  finish_callback_.Run(true);
+  finish_callback_.Run(true, webapk_package_);
   delete this;
 }
 
 void WebApkInstaller::OnFailure() {
-  finish_callback_.Run(false);
+  finish_callback_.Run(false, webapk_package_);
   delete this;
 }