Mac: Fix black flashing during tab switch

content/browser/compositor/browser_compositor_view_mac.mm

Index: content/browser/compositor/browser_compositor_view_mac.mm
diff --git a/content/browser/compositor/browser_compositor_view_mac.mm b/content/browser/compositor/browser_compositor_view_mac.mm
index 322183d0570ff20a19ef6871219263b4ee653609..472c17fab837a504b65f8698ee36915426d73721 100644
--- a/content/browser/compositor/browser_compositor_view_mac.mm
+++ b/content/browser/compositor/browser_compositor_view_mac.mm
@@ -48,9 +48,12 @@ BrowserCompositorMac::BrowserCompositorMac()
           RenderWidgetResizeHelper::Get()->task_runner()) {
   compositor_.SetLocksWillTimeOut(false);
   Suspend();
+  compositor_.AddObserver(this);
 }
 
-BrowserCompositorMac::~BrowserCompositorMac() {}
+BrowserCompositorMac::~BrowserCompositorMac() {
+  compositor_.RemoveObserver(this);
+}
 
 void BrowserCompositorMac::Suspend() {
   compositor_suspended_lock_ = compositor_.GetCompositorLock();
@@ -60,6 +63,13 @@ void BrowserCompositorMac::Unsuspend() {
   compositor_suspended_lock_ = nullptr;
 }
 
+void BrowserCompositorMac::OnCompositingDidCommit(
+    ui::Compositor* compositor_that_did_commit) {
+  DCHECK_EQ(compositor_that_did_commit, compositor());
+  content::ImageTransportFactory::GetInstance()
+      ->SetCompositorSuspendedForRecycle(compositor(), false);
+}
+
 // static
 scoped_ptr<BrowserCompositorMac> BrowserCompositorMac::Create() {
   if (g_recyclable_browser_compositor.Get())
@@ -71,8 +81,8 @@ scoped_ptr<BrowserCompositorMac> BrowserCompositorMac::Create() {
 void BrowserCompositorMac::Recycle(
     scoped_ptr<BrowserCompositorMac> compositor) {
   DCHECK(compositor);
-  content::ImageTransportFactory::GetInstance()->OnCompositorRecycled(
-      compositor->compositor());
+  content::ImageTransportFactory::GetInstance()
+      ->SetCompositorSuspendedForRecycle(compositor->compositor(), true);
 
   // It is an error to have a browser compositor continue to exist after
   // shutdown.