[chrome.dial] Adds chrome.dial.fetchDeviceDecription API.

chrome/browser/extensions/api/dial/dial_api.cc

Index: chrome/browser/extensions/api/dial/dial_api.cc
diff --git a/chrome/browser/extensions/api/dial/dial_api.cc b/chrome/browser/extensions/api/dial/dial_api.cc
index 6f43b17aaf0ade8c3e4e533e98cdbe6a0cfa6358..a67117204369ecdfb7834159c23a89e9f910b6e2 100644
--- a/chrome/browser/extensions/api/dial/dial_api.cc
+++ b/chrome/browser/extensions/api/dial/dial_api.cc
@@ -8,14 +8,17 @@
 #include <utility>
 #include <vector>
 
+#include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "base/time/time.h"
+#include "chrome/browser/extensions/api/dial/device_description_fetcher.h"
 #include "chrome/browser/extensions/api/dial/dial_api_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/dial.h"
 #include "content/public/browser/browser_thread.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_system.h"
+#include "url/gurl.h"
 
 using base::TimeDelta;
 using content::BrowserThread;
@@ -50,10 +53,12 @@ DialAPI::~DialAPI() {}
 DialRegistry* DialAPI::dial_registry() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (!dial_registry_.get()) {
-    dial_registry_.reset(new DialRegistry(this,
-        TimeDelta::FromSeconds(kDialRefreshIntervalSecs),
-        TimeDelta::FromSeconds(kDialExpirationSecs),
-        kDialMaxDevices));
+    dial_registry_.reset(new DialRegistry(
+        this, TimeDelta::FromSeconds(kDialRefreshIntervalSecs),
+        TimeDelta::FromSeconds(kDialExpirationSecs), kDialMaxDevices));
+    if (!test_device_data_.device_id().empty()) {
+      dial_registry_->AddDeviceForTest(test_device_data_);
+    }
   }
   return dial_registry_.get();
 }
@@ -147,6 +152,13 @@ void DialAPI::SendErrorOnUIThread(const DialRegistry::DialErrorCode code) {
 
 void DialAPI::ShutdownOnUIThread() {}
 
+void DialAPI::SetDeviceForTest(
+    const DialDeviceData& device_data,
+    const DialDeviceDescription& device_description) {
+  test_device_data_ = device_data;
+  test_device_description_ = device_description;
+}
+
 namespace api {
 
 DialDiscoverNowFunction::DialDiscoverNowFunction()
@@ -171,6 +183,74 @@ bool DialDiscoverNowFunction::Respond() {
   return true;
 }
 
+DialFetchDeviceDescriptionFunction::DialFetchDeviceDescriptionFunction()
+    : dial_(nullptr) {}
+
+DialFetchDeviceDescriptionFunction::~DialFetchDeviceDescriptionFunction() {}
+
+bool DialFetchDeviceDescriptionFunction::RunAsync() {
+  dial_ = DialAPIFactory::GetForBrowserContext(browser_context()).get();
+  params_ = api::dial::FetchDeviceDescription::Params::Create(*args_);
+  EXTENSION_FUNCTION_VALIDATE(params_.get());
+
+  // DialRegistry lives on the IO thread.  Hop on over there to get the URL to
+  // fetch.
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+                          base::Bind(&DialFetchDeviceDescriptionFunction::
+                                         GetDeviceDescriptionUrlOnIOThread,
+                                     this, params_->device_label));
+  return true;
+}
+
+void DialFetchDeviceDescriptionFunction::GetDeviceDescriptionUrlOnIOThread(
+    const std::string& label) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  const GURL& device_description_url =
+      dial_->dial_registry()->GetDeviceDescriptionURL(label);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,

[imcheng, 2016/12/28 05:36:45]

Hmm.. I think the fetch should happen in IO thread. What's the reason for it to
be on UI thread?

[mark a. foltz, 2017/01/04 00:20:16]

The URLFetcher takes a RequestContext generated by the user's Profile (which
must be done on the UI thread), and posts a task to the IO thread on the
caller's behalf.

https://cs.chromium.org/chromium/src/net/url_request/url_fetcher_core.cc?rcl=...

+      base::Bind(&DialFetchDeviceDescriptionFunction::MaybeStartFetch, this,
+                 device_description_url));
+}
+
+void DialFetchDeviceDescriptionFunction::MaybeStartFetch(const GURL& url) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  if (url.is_empty()) {
+    SetError("Device not found");
+    SendResponse(false);
+    return;
+  }
+
+  if (dial_->test_device_data_.device_description_url() == url) {
+    OnFetchComplete(dial_->test_device_description_);
+    return;
+  }
+
+  device_description_fetcher_ = base::MakeUnique<DeviceDescriptionFetcher>(
+      url, Profile::FromBrowserContext(browser_context()),
+      base::BindOnce(&DialFetchDeviceDescriptionFunction::OnFetchComplete,
+                     this),
+      base::BindOnce(&DialFetchDeviceDescriptionFunction::OnFetchError, this));
+
+  device_description_fetcher_->Start();
+}
+
+void DialFetchDeviceDescriptionFunction::OnFetchComplete(
+    const DialDeviceDescription& result) {
+  api::dial::DialDeviceDescription device_description;
+  device_description.device_label = params_->device_label;
+  device_description.app_url = result.app_url.spec();
+  device_description.device_description = result.device_description;
+  SetResult(device_description.ToValue());
+  SendResponse(true);
+}
+
+void DialFetchDeviceDescriptionFunction::OnFetchError(
+    const std::string& message) {
+  SetError(message);
+  SendResponse(false);
+}
+
 }  // namespace api
 
 }  // namespace extensions