Desktop chrome tab capture-chooseDesktopMedia()

chrome/browser/media/desktop_media_list_ash.cc

Index: chrome/browser/media/desktop_media_list_ash.cc
diff --git a/chrome/browser/media/desktop_media_list_ash.cc b/chrome/browser/media/desktop_media_list_ash.cc
index a9ab1a4224b0d9c05d9e9ecf0fe2c367df90dc2b..74f1161bbf4e8b283ecddce3ba1dd0c98b86ecaf 100644
--- a/chrome/browser/media/desktop_media_list_ash.cc
+++ b/chrome/browser/media/desktop_media_list_ash.cc
@@ -15,8 +15,14 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/media/desktop_media_list_observer.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/grit/generated_resources.h"
+#include "components/favicon/content/content_favicon_driver.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
 #include "media/base/video_util.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/compositor/dip_util.h"
@@ -171,6 +177,72 @@ void DesktopMediaListAsh::EnumerateWindowsForRoot(
   }
 }
 
+void DesktopMediaListAsh::EnumerateTabs(
+    std::vector<DesktopMediaListAsh::SourceDescription>* sources) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  std::map<base::TimeTicks, SourceDescription> tab_map;
+
+  // Get all tabs/webcontents' ids for a user profile

[Avi (use Gerrit), 2016/01/08 17:11:38]

Full sentences; end it with a period.

[GeorgeZ, 2016/01/08 19:39:02]

Done.

+  Profile* profile = ProfileManager::GetLastUsedProfileAllowedByPolicy();
+  std::vector<Browser*> browsers = FindAllTabbedBrowsersWithProfile(
+      profile, chrome::HOST_DESKTOP_TYPE_NATIVE);
+
+  std::vector<scoped_ptr<MediaListWebContentsObserver>> observers;
+  for (auto browser : browsers) {
+    TabStripModel* tab_strip_model = browser->tab_strip_model();
+    DCHECK(tab_strip_model);
+
+    for (int i = 0; i < tab_strip_model->count(); i++) {
+      content::WebContents* contents = tab_strip_model->GetWebContentsAt(i);
+      // Use observer to keep track the state of WebContents.
+      scoped_ptr<MediaListWebContentsObserver> observer(
+          new MediaListWebContentsObserver(contents));
+      observers.push_back(std::move(observer));
+    }
+  }
+
+  // For each tab, get its title and favicon.
+  for (size_t i = 0; i < observers.size(); i++) {
+    // If the WebContents has been destroyed, a nullptr will return;

[Avi (use Gerrit), 2016/01/08 17:11:38]

How could the WebContents have been destroyed from the time you grabbed it ten
lines up, and now? We're on the UI thread, and WebContents creation and
destruction happens on that thread.

It's completely OK to walk the TabStripModel, get all the WebContents, and do
stuff with them. There's no danger of them disappearing on you, so don't worry
:)

Remove the MediaListWebContentsObserver class and all of this paranoid code.
It's not needed.

[GeorgeZ, 2016/01/08 19:39:02]

Thanks for the explanation here.

Done.

+    content::WebContents* contents = observers[i]->web_contents();
+    if (contents == nullptr)
+      continue;
+
+    content::RenderFrameHost* const main_frame = contents->GetMainFrame();
+    DCHECK(main_frame);
+    DesktopMediaID media_id(
+        DesktopMediaID::TYPE_TAB, DesktopMediaID::kNullId,
+        content::WebContentsMediaCaptureId(main_frame->GetProcess()->GetID(),
+                                           main_frame->GetRoutingID()));
+
+    // Create display tab title.
+    base::string16 title = l10n_util::GetStringFUTF16(
+        IDS_DESKTOP_MEDIA_PICKER_CHROME_TAB_TITLE, contents->GetTitle());
+
+    // Get tab's last active time stamp.
+    base::TimeTicks t = contents->GetLastActiveTime();
+    tab_map.insert(std::make_pair(t, SourceDescription(media_id, title)));
+
+    // Create thumbnail based on favicon for tab.
+    favicon::FaviconDriver* favicon_driver =
+        favicon::ContentFaviconDriver::FromWebContents(contents);
+    if (favicon_driver) {
+      gfx::Image tab_icon = favicon_driver->GetFavicon();
+      tab_map[t].thumbnail =
+          CreateEnlargedFaviconImage(thumbnail_size_, tab_icon);
+    }
+  }
+
+  // Add timely sorted tab sources into vector. Most recent one first.
+  for (auto it = tab_map.rbegin(); it != tab_map.rend(); ++it) {
+    SourceDescription& source = it->second;
+    sources->push_back(source);
+    if (!it->second.thumbnail.isNull())
+      OnThumbnailCaptured(source.id, gfx::Image(source.thumbnail));
+  }
+}
+
 void DesktopMediaListAsh::EnumerateSources(
     std::vector<DesktopMediaListAsh::SourceDescription>* sources) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
@@ -211,6 +283,9 @@ void DesktopMediaListAsh::EnumerateSources(
       EnumerateWindowsForRoot(
           sources, root_windows[i], ash::kShellWindowId_DockedContainer);
     }
+
+    if (source_types_ & TABS)
+      EnumerateTabs(sources);
   }
 }