VR: keep track of all pages that are recording audio/video/screen

chrome/browser/android/vr_shell/vr_shell.cc

Index: chrome/browser/android/vr_shell/vr_shell.cc
diff --git a/chrome/browser/android/vr_shell/vr_shell.cc b/chrome/browser/android/vr_shell/vr_shell.cc
index 037c2c70c39e1ef9dc42150bb16b0166df2ce78b..6ed846f55198668442522af00b7de9d90995fd9a 100644
--- a/chrome/browser/android/vr_shell/vr_shell.cc
+++ b/chrome/browser/android/vr_shell/vr_shell.cc
@@ -317,6 +317,10 @@ void VrShell::OnTabListCreated(JNIEnv* env,
                                const JavaParamRef<jobject>& obj,
                                jobjectArray tabs,
                                jobjectArray incognito_tabs) {
+  number_of_tabs_capturing_audio_ = 0;
+  number_of_tabs_capturing_video_ = 0;
+  number_of_tabs_capturing_screen_ = 0;
+
   ProcessTabArray(env, tabs, false);
   ProcessTabArray(env, incognito_tabs, true);
   ui_->FlushTabList();
@@ -329,6 +333,17 @@ void VrShell::ProcessTabArray(JNIEnv* env, jobjectArray tabs, bool incognito) {
     TabAndroid* tab =
         TabAndroid::GetNativeTab(env, JavaParamRef<jobject>(env, jtab));
     ui_->AppendToTabList(incognito, tab->GetAndroidId(), tab->GetTitle());
+    if (tab->web_contents() != web_contents_) {
+      scoped_refptr<MediaStreamCaptureIndicator> indicator =
+          MediaCaptureDevicesDispatcher::GetInstance()
+              ->GetMediaStreamCaptureIndicator();
+      if (indicator->IsCapturingAudio(tab->web_contents()))

[cjgrant, 2017/05/23 20:38:18]

If this method is reliable enough to use with other tabs, why not use it to
maintain the current tab's capture state as well?  This seems really clean.

[asimjour1, 2017/05/23 20:49:19]

Current tab can change its current state. So we have to poll the flag every 0.01
seconds. We don't need to do the same for the background tabs, so it will be
more efficient if we don't iterate on all tabs every 0.01 seconds.

[cjgrant, 2017/05/24 13:56:25]

A few more questions:
- Can a background tab ever change state?
- This code explicitly skips the current tab when counting right?  If that's the
case, won't it eliminate the current tab from being counted?  I'll message you
offline to understand this better.

[asimjour1, 2017/05/25 14:38:37]

I moved the code from here, and check all tabs every time.

+        number_of_tabs_capturing_audio_++;
+      if (indicator->IsCapturingVideo(tab->web_contents()))
+        number_of_tabs_capturing_video_++;
+      if (indicator->IsBeingMirrored(tab->web_contents()))
+        number_of_tabs_capturing_screen_++;
+    }
   }
 }
 
@@ -574,18 +589,33 @@ void VrShell::PollMediaAccessFlag() {
       MediaCaptureDevicesDispatcher::GetInstance()
           ->GetMediaStreamCaptureIndicator();
   bool is_capturing_audio = indicator->IsCapturingAudio(web_contents_);
-  if (is_capturing_audio != is_capturing_audio_)
-    ui_->SetAudioCapturingIndicator(is_capturing_audio);
+  if (is_capturing_audio != is_capturing_audio_) {
+    number_of_tabs_capturing_audio_ += is_capturing_audio ? 1 : -1;

[cjgrant, 2017/05/24 13:56:25]

style guide prefers "num_tabs_capturing_audio_" (and shorter is better :)  Then
its:
ui_->setAudiocapturingIndicator(num_tabs_... > 0);

[asimjour1, 2017/05/25 14:38:37]

Done.

+    if (number_of_tabs_capturing_audio_ > 0)
+      ui_->SetAudioCapturingIndicator(true);
+    else
+      ui_->SetAudioCapturingIndicator(false);
+  }
   is_capturing_audio_ = is_capturing_audio;
 
   bool is_capturing_video = indicator->IsCapturingVideo(web_contents_);
-  if (is_capturing_video != is_capturing_video_)
-    ui_->SetVideoCapturingIndicator(is_capturing_video);
+  if (is_capturing_video != is_capturing_video_) {
+    number_of_tabs_capturing_video_ += is_capturing_video ? 1 : -1;
+    if (number_of_tabs_capturing_video_ > 0)
+      ui_->SetVideoCapturingIndicator(true);
+    else
+      ui_->SetVideoCapturingIndicator(false);
+  }
   is_capturing_video_ = is_capturing_video;
 
   bool is_capturing_screen = indicator->IsBeingMirrored(web_contents_);
-  if (is_capturing_screen != is_capturing_screen_)
-    ui_->SetScreenCapturingIndicator(is_capturing_screen);
+  if (is_capturing_screen != is_capturing_screen_) {
+    number_of_tabs_capturing_screen_ += is_capturing_screen ? 1 : -1;
+    if (number_of_tabs_capturing_screen_ > 0)
+      ui_->SetScreenCapturingIndicator(true);
+    else
+      ui_->SetScreenCapturingIndicator(false);
+  }
   is_capturing_screen_ = is_capturing_screen;
 }