Revert 120111 - Defer render_widget draw until host window is available

In accelerated compositing mode we can't start rendering until the
native window (HWND/gtk widget) are created on Windows and GTK without
aura. For most render_widgets the code today is racy, but for
window.open() and similar creation paths this is a race that we pretty
much always lose. This defers the first DoDeferredUpdate on a render_widget
until its host_window_ is available.

Also defers querying for GL_CHROMIUM_supports_swapbuffers_callback
extension until the first draw, since the context isn't ready until the
host window is available.

BUG=106815
TEST=start with --force-compositing-mode and --show-fps-counter, load up
a page that uses window.open() to open a popup, and confirm that the
popup is in compositing mode


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=119977

Review URL: http://codereview.chromium.org/9225050

TBR=jamesr@chromium.org
Review URL: https://chromiumcodereview.appspot.com/9307043

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@120130 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 9 insertions, 33 deletions

diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 69bfb28..c8eb610 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -397,8 +397,6 @@ RenderViewImpl::RenderViewImpl(
       cached_is_main_frame_pinned_to_right_(false),
       cached_has_main_frame_horizontal_scrollbar_(false),
       cached_has_main_frame_vertical_scrollbar_(false),
-      context_has_swapbuffers_complete_callback_(false),
-      queried_for_swapbuffers_complete_callback_(false),
       ALLOW_THIS_IN_INITIALIZER_LIST(cookie_jar_(this)),
       geolocation_dispatcher_(NULL),
       speech_input_dispatcher_(NULL),
@@ -4497,21 +4495,12 @@ bool RenderViewImpl::SupportsAsynchronousSwapBuffers() {
   if (WebWidgetHandlesCompositorScheduling())
     return false;
 
-  if (queried_for_swapbuffers_complete_callback_)
-    return context_has_swapbuffers_complete_callback_;
-
-  queried_for_swapbuffers_complete_callback_ = true;
-
   WebKit::WebGraphicsContext3D* context = webview()->graphicsContext3D();
-  if (context) {
-    context->makeContextCurrent();
-    std::string extensions(context->getRequestableExtensionsCHROMIUM().utf8());
-    context_has_swapbuffers_complete_callback_ =
-        extensions.find("GL_CHROMIUM_swapbuffers_complete_callback")
-            != std::string::npos;
-  }
-
-  return context_has_swapbuffers_complete_callback_;
+  if (!context)
+    return false;
+  std::string extensions(context->getRequestableExtensionsCHROMIUM().utf8());
+  return extensions.find("GL_CHROMIUM_swapbuffers_complete_callback") !=
+      std::string::npos;
 }
 
 void RenderViewImpl::OnSetFocus(bool enable) {
diff --git a/content/renderer/render_view_impl.h b/content/renderer/render_view_impl.h
index 083ab85..b892a80 100644
--- a/content/renderer/render_view_impl.h
+++ b/content/renderer/render_view_impl.h
@@ -1135,13 +1135,6 @@ class RenderViewImpl : public RenderWidget,
   std::set<gfx::PluginWindowHandle> fake_plugin_window_handles_;
 #endif
 
-  // When this view is composited, the context used for compositing may or may
-  // not support the GL_CHROMIUM_swapbuffers_complete_callback extension. Since
-  // querying for the existence of this extension is expensive we cache the
-  // result. These are used to implement SupportsAsynchronousSwapBuffers().
-  bool context_has_swapbuffers_complete_callback_;
-  bool queried_for_swapbuffers_complete_callback_;
-
   // Helper objects ------------------------------------------------------------
 
   RendererWebCookieJarImpl cookie_jar_;
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 6b16fa7..3df2a99 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -175,8 +175,6 @@ void RenderWidget::CompleteInit(gfx::NativeViewId parent_hwnd) {
 
   host_window_ = parent_hwnd;
 
-  DoDeferredUpdate();
-
   Send(new ViewHostMsg_RenderViewReady(routing_id_));
 }
 
@@ -739,11 +737,6 @@ void RenderWidget::DoDeferredUpdate() {
 
   if (!webwidget_)
     return;
-
-  if (!host_window_) {
-    TRACE_EVENT0("renderer", "EarlyOut_NoHostWindow");
-    return;
-  }
   if (update_reply_pending_) {
     TRACE_EVENT0("renderer", "EarlyOut_UpdateReplyPending");
     return;
@@ -762,9 +755,6 @@ void RenderWidget::DoDeferredUpdate() {
     return;
   }
 
-  if (is_accelerated_compositing_active_)
-    using_asynchronous_swapbuffers_ = SupportsAsynchronousSwapBuffers();
-
   // Tracking of frame rate jitter
   base::TimeTicks frame_begin_ticks = base::TimeTicks::Now();
   AnimateIfNeeded();
@@ -1020,6 +1010,10 @@ void RenderWidget::didActivateCompositor(int compositor_identifier) {
   is_accelerated_compositing_active_ = true;
   Send(new ViewHostMsg_DidActivateAcceleratedCompositing(
       routing_id_, is_accelerated_compositing_active_));
+
+  // Note: asynchronous swapbuffer support currently only matters if
+  // compositing scheduling happens on the RenderWidget.
+  using_asynchronous_swapbuffers_ = SupportsAsynchronousSwapBuffers();
 }
 
 void RenderWidget::didDeactivateCompositor() {