1 files changed, 160 insertions, 0 deletions
diff --git a/chromium/content/browser/renderer_host/display_link_mac.cc b/chromium/content/browser/renderer_host/display_link_mac.cc
new file mode 100644
index 00000000000..b4592a9f3b7
--- /dev/null
+++ b/chromium/content/browser/renderer_host/display_link_mac.cc
@@ -0,0 +1,160 @@
+// 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 "content/browser/renderer_host/display_link_mac.h"
+
+#include "base/debug/trace_event.h"
+#include "base/logging.h"
+
+namespace base {
+
+template<>
+struct ScopedTypeRefTraits<CVDisplayLinkRef> {
+  static void Retain(CVDisplayLinkRef object) {
+    CVDisplayLinkRetain(object);
+  }
+  static void Release(CVDisplayLinkRef object) {
+    CVDisplayLinkRelease(object);
+  }
+};
+
+}  // namespace base
+
+namespace content {
+
+// static
+scoped_refptr<DisplayLinkMac> DisplayLinkMac::GetForDisplay(
+    CGDirectDisplayID display_id) {
+  // Return the existing display link for this display, if it exists.
+  DisplayMap::iterator found = display_map_.Get().find(display_id);
+  if (found != display_map_.Get().end()) {
+    return found->second;
+  }
+
+  CVReturn ret = kCVReturnSuccess;
+
+  base::ScopedTypeRef<CVDisplayLinkRef> display_link;
+  ret = CVDisplayLinkCreateWithCGDisplay(
+      display_id,
+      display_link.InitializeInto());
+  if (ret != kCVReturnSuccess) {
+    LOG(ERROR) << "CVDisplayLinkCreateWithActiveCGDisplays failed: " << ret;
+    return NULL;
+  }
+
+  scoped_refptr<DisplayLinkMac> display_link_mac;
+  display_link_mac = new DisplayLinkMac(display_id, display_link);
+
+  ret = CVDisplayLinkSetOutputCallback(
+      display_link_mac->display_link_,
+      &DisplayLinkCallback,
+      display_link_mac.get());
+  if (ret != kCVReturnSuccess) {
+    LOG(ERROR) << "CVDisplayLinkSetOutputCallback failed: " << ret;
+    return NULL;
+  }
+
+  return display_link_mac;
+}
+
+DisplayLinkMac::DisplayLinkMac(
+    CGDirectDisplayID display_id,
+    base::ScopedTypeRef<CVDisplayLinkRef> display_link)
+      : display_id_(display_id),
+        display_link_(display_link),
+        stop_timer_(
+            FROM_HERE, base::TimeDelta::FromSeconds(1),
+            this, &DisplayLinkMac::StopDisplayLink),
+        timebase_and_interval_valid_(false) {
+  DCHECK(display_map_.Get().find(display_id) == display_map_.Get().end());
+  display_map_.Get().insert(std::make_pair(display_id_, this));
+}
+
+DisplayLinkMac::~DisplayLinkMac() {
+  if (CVDisplayLinkIsRunning(display_link_))
+    CVDisplayLinkStop(display_link_);
+
+  DisplayMap::iterator found = display_map_.Get().find(display_id_);
+  DCHECK(found != display_map_.Get().end());
+  DCHECK(found->second == this);
+  display_map_.Get().erase(found);
+}
+
+bool DisplayLinkMac::GetVSyncParameters(
+    base::TimeTicks* timebase, base::TimeDelta* interval) {
+  StartOrContinueDisplayLink();
+
+  base::AutoLock lock(lock_);
+  if (!timebase_and_interval_valid_)
+    return false;
+
+  *timebase = timebase_;
+  *interval = interval_;
+  return true;
+}
+
+void DisplayLinkMac::Tick(const CVTimeStamp* cv_time) {
+  TRACE_EVENT0("browser", "DisplayLinkMac::GetVSyncParameters");
+  base::AutoLock lock(lock_);
+
+  // Verify that videoRefreshPeriod is 32 bits.
+  DCHECK((cv_time->videoRefreshPeriod & ~0xffffFFFFull) == 0ull);
+
+  // Verify that the numerator and denominator make some sense.
+  uint32 numerator = static_cast<uint32>(cv_time->videoRefreshPeriod);
+  uint32 denominator = cv_time->videoTimeScale;
+  if (numerator <= 0 || denominator <= 0) {
+    LOG(WARNING) << "Unexpected numerator or denominator, bailing.";
+    return;
+  }
+
+  timebase_ = base::TimeTicks::FromInternalValue(
+      cv_time->hostTime / 1000);
+  interval_ = base::TimeDelta::FromMicroseconds(
+      1000000 * static_cast<int64>(numerator) / denominator);
+  timebase_and_interval_valid_ = true;
+}
+
+void DisplayLinkMac::StartOrContinueDisplayLink() {
+  // Reset the timer, so that the display link won't be turned off for another
+  // second.
+  stop_timer_.Reset();
+
+  if (CVDisplayLinkIsRunning(display_link_))
+    return;
+
+  CVReturn ret = CVDisplayLinkStart(display_link_);
+  if (ret != kCVReturnSuccess) {
+    LOG(ERROR) << "CVDisplayLinkStart failed: " << ret;
+  }
+}
+
+void DisplayLinkMac::StopDisplayLink() {
+  if (!CVDisplayLinkIsRunning(display_link_))
+    return;
+
+  CVReturn ret = CVDisplayLinkStop(display_link_);
+  if (ret != kCVReturnSuccess) {
+    LOG(ERROR) << "CVDisplayLinkStop failed: " << ret;
+  }
+}
+
+CVReturn DisplayLinkMac::DisplayLinkCallback(
+    CVDisplayLinkRef display_link,
+    const CVTimeStamp* now,
+    const CVTimeStamp* output_time,
+    CVOptionFlags flags_in,
+    CVOptionFlags* flags_out,
+    void* context) {
+  DisplayLinkMac* display_link_mac = static_cast<DisplayLinkMac*>(context);
+  display_link_mac->Tick(output_time);
+  return kCVReturnSuccess;
+}
+
+// static
+base::LazyInstance<DisplayLinkMac::DisplayMap>
+    DisplayLinkMac::display_map_ = LAZY_INSTANCE_INITIALIZER;
+
+}  // content
+