Tab/Desktop capture: Fix for super-old frame after resume.

media/capture/content/screen_capture_device_core.cc

 // Copyright 2014 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 "media/capture/content/screen_capture_device_core.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 51 matching lines @@
   capture_machine_->Start(
       oracle_proxy_, params,
       base::Bind(&ScreenCaptureDeviceCore::CaptureStarted, AsWeakPtr()));
 
   TransitionStateTo(kCapturing);
 }
 
 void ScreenCaptureDeviceCore::RequestRefreshFrame() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  if (state_ != kCapturing && state_ != kSuspended)
+  if (state_ != kCapturing)
     return;
 
+  // Try to use the less resource-intensive "passive" refresh mechanism, unless
+  // this is the first refresh following a Resume().
+  if (force_active_refresh_once_) {
+    capture_machine_->MaybeCaptureForRefresh();
+    force_active_refresh_once_ = false;
+    return;
+  }
+
+  // Make a best-effort attempt at a passive refresh, but fall-back to an active
+  // refresh if that fails.
   if (oracle_proxy_->AttemptPassiveRefresh())
     return;
   capture_machine_->MaybeCaptureForRefresh();
 }
 
 void ScreenCaptureDeviceCore::Suspend() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (state_ != kCapturing)
     return;
 
   TransitionStateTo(kSuspended);
 
   capture_machine_->Suspend();
 }
 
 void ScreenCaptureDeviceCore::Resume() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (state_ != kSuspended)
     return;
 
+  force_active_refresh_once_ = true;
   TransitionStateTo(kCapturing);
 
   capture_machine_->Resume();
 }
 
 void ScreenCaptureDeviceCore::StopAndDeAllocate() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (state_ != kCapturing && state_ != kSuspended)
     return;
@@ skipping 15 matching lines @@
 }
 
 void ScreenCaptureDeviceCore::CaptureStarted(bool success) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (!success)
     Error(FROM_HERE, "Failed to start capture machine.");
 }
 
 ScreenCaptureDeviceCore::ScreenCaptureDeviceCore(
     std::unique_ptr<VideoCaptureMachine> capture_machine)
-    : state_(kIdle), capture_machine_(std::move(capture_machine)) {
+    : state_(kIdle),
+      capture_machine_(std::move(capture_machine)),
+      force_active_refresh_once_(false) {
   DCHECK(capture_machine_.get());
 }
 
 ScreenCaptureDeviceCore::~ScreenCaptureDeviceCore() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(state_ != kCapturing && state_ != kSuspended);
   if (capture_machine_) {
     capture_machine_->Stop(
         base::Bind(&DeleteCaptureMachine, base::Passed(&capture_machine_)));
   }
@@ skipping 23 matching lines @@
     return;
 
   if (oracle_proxy_.get())
     oracle_proxy_->ReportError(from_here, reason);
 
   StopAndDeAllocate();
   TransitionStateTo(kError);
 }
 
 }  // namespace media