Delete background tab IOSurfaces on Mac.

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index 89cd97c42e90acc0b2b13d3cae6eeff9c2ba0b87..1af40343dc8b290dcde0eb1ff491761b87335100 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -24,6 +24,7 @@
 #include "content/browser/plugin_process_host.h"
 #import "content/browser/renderer_host/accelerated_plugin_view_mac.h"
 #include "content/browser/renderer_host/backing_store_mac.h"
+#include "content/browser/renderer_host/backing_store_manager.h"
 #include "content/browser/renderer_host/compositing_iosurface_mac.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
@@ -263,8 +264,7 @@ RenderWidgetHostViewMac::RenderWidgetHostViewMac(RenderWidgetHost* widget)
       can_compose_inline_(true),
       is_loading_(false),
       is_hidden_(false),
-      weak_factory_(this),
-      compositing_surface_(gfx::kNullPluginWindow) {
+      weak_factory_(this) {
   // |cocoa_view_| owns us and we will be deleted when |cocoa_view_|
   // goes away.  Since we autorelease it, our caller must put
   // |GetNativeView()| into the view hierarchy right after calling us.
@@ -961,7 +961,12 @@ void RenderWidgetHostViewMac::CompositorSwapBuffers(uint64 surface_handle,
   if (compositing_iosurface_.get() && !is_hidden_) {
     last_frame_was_accelerated_ = true;
     compositing_iosurface_->SetIOSurface(surface_handle);
-    [cocoa_view_ setNeedsDisplay:YES];
+    // No need for presenting if we're already in a drawRect (it will be done
+    // later).
+    if (!about_to_validate_and_paint_) {
+      compositing_iosurface_->DrawIOSurface(cocoa_view_);
+      AckPendingCompositorSwapBuffers();
+    }
   } else {
     AckPendingCompositorSwapBuffers();
   }
@@ -987,7 +992,9 @@ void RenderWidgetHostViewMac::AcceleratedSurfaceBuffersSwapped(
       "RenderWidgetHostViewMac::AcceleratedSurfaceBuffersSwapped");
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  if (params.window == compositing_surface_) {
+  // Compositor window is always gfx::kNullPluginWindow.
+  // TODO(jbates) This will be removed when there are no plugin windows.
+  if (params.window == gfx::kNullPluginWindow) {
     CompositorSwapBuffers(params.surface_handle, params.route_id, gpu_host_id);
   } else {
     // Deprecated accelerated plugin code path.
@@ -1017,7 +1024,9 @@ void RenderWidgetHostViewMac::AcceleratedSurfacePostSubBuffer(
       "RenderWidgetHostViewMac::AcceleratedSurfacePostSubBuffer");
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  if (params.window == compositing_surface_) {
+  // Compositor window is always gfx::kNullPluginWindow.
+  // TODO(jbates) This will be removed when there are no plugin windows.
+  if (params.window == gfx::kNullPluginWindow) {
     CompositorSwapBuffers(params.surface_handle, params.route_id, gpu_host_id);
   } else {
     // Deprecated accelerated plugin code path.
@@ -1043,6 +1052,23 @@ void RenderWidgetHostViewMac::AcceleratedSurfacePostSubBuffer(
 }
 
 void RenderWidgetHostViewMac::AcceleratedSurfaceSuspend() {
+  if (compositing_iosurface_.get())
+    compositing_iosurface_->UnrefIOSurface();
+}
+
+bool RenderWidgetHostViewMac::HasAcceleratedSurface(
+      const gfx::Size& desired_size) {
+  return last_frame_was_accelerated_ &&
+         compositing_iosurface_.get() &&
+         compositing_iosurface_->HasIOSurface() &&
+         (desired_size.IsEmpty() ||
+          compositing_iosurface_->io_surface_size() == desired_size);
+}
+
+void RenderWidgetHostViewMac::AboutToWaitForUpdateMsg() {
+  // We want to get a fresh frame from the renderer, so ack any pending swaps to
+  // allow the renderer to produce new frames.
+  AckPendingCompositorSwapBuffers();
 }
 
 void RenderWidgetHostViewMac::OnAcceleratedCompositingStateChange() {
@@ -1065,8 +1091,9 @@ gfx::Rect RenderWidgetHostViewMac::GetRootWindowBounds() {
 }
 
 gfx::GLSurfaceHandle RenderWidgetHostViewMac::GetCompositingSurface() {
-  // compositing_surface_ is always gfx::kNullPluginWindow.
-  return gfx::GLSurfaceHandle(compositing_surface_, true);
+  // Compositor window is always gfx::kNullPluginWindow.
+  // TODO(jbates) This will be removed when there are no plugin windows.
+  return gfx::GLSurfaceHandle(gfx::kNullPluginWindow, true);
 }
 
 void RenderWidgetHostViewMac::DrawAcceleratedSurfaceInstance(
@@ -1357,6 +1384,7 @@ void RenderWidgetHostViewMac::SetTextInputActive(bool active) {
 }
 
 - (void)mouseEvent:(NSEvent*)theEvent {
+  TRACE_EVENT0("browser", "RenderWidgetHostViewCocoa::mouseEvent");
   if (delegate_ && [delegate_ respondsToSelector:@selector(handleEvent:)]) {
     BOOL handled = [delegate_ handleEvent:theEvent];
     if (handled)
@@ -1518,6 +1546,7 @@ void RenderWidgetHostViewMac::SetTextInputActive(bool active) {
 }
 
 - (void)keyEvent:(NSEvent*)theEvent wasKeyEquivalent:(BOOL)equiv {
+  TRACE_EVENT0("browser", "RenderWidgetHostViewCocoa::keyEvent");
   DCHECK([theEvent type] != NSKeyDown ||
          !equiv == !([theEvent modifierFlags] & NSCommandKeyMask));
 
@@ -1843,6 +1872,7 @@ void RenderWidgetHostViewMac::SetTextInputActive(bool active) {
 }
 
 - (void)drawRect:(NSRect)dirtyRect {
+  TRACE_EVENT0("browser", "RenderWidgetHostViewCocoa::drawRect");
   if (!renderWidgetHostView_->render_widget_host_) {
     // TODO(shess): Consider using something more noticable?
     [[NSColor whiteColor] set];
@@ -1850,30 +1880,46 @@ void RenderWidgetHostViewMac::SetTextInputActive(bool active) {
     return;
   }
 
+  DCHECK(!renderWidgetHostView_->about_to_validate_and_paint_);
+
+  // GetBackingStore works for both software and accelerated frames. If a
+  // SwapBuffers occurs while GetBackingStore is blocking, we will continue to
+  // blit the IOSurface below.
+  renderWidgetHostView_->about_to_validate_and_paint_ = true;
+  BackingStoreMac* backingStore = static_cast<BackingStoreMac*>(
+      renderWidgetHostView_->render_widget_host_->GetBackingStore(true));
+  renderWidgetHostView_->about_to_validate_and_paint_ = false;
+
   const gfx::Rect damagedRect([self flipNSRectToRect:dirtyRect]);
 
   if (renderWidgetHostView_->last_frame_was_accelerated_) {
-    // Draw transparency to expose the GL underlay:
-    // TODO(jbates) avoid doing this every frame.
-    [[NSColor clearColor] set];
-    NSRectFill(dirtyRect);
+    // Delete software backingstore.
+    // TODO(jbates) Only do this on first GPU frame after software frame.
+    BackingStoreManager::RemoveBackingStore(
+        renderWidgetHostView_->render_widget_host_);
+
+    {
+      TRACE_EVENT0("browser", "NSRectFill");
+      // Draw transparency to expose the GL underlay:
+      // TODO(jbates) avoid doing this every frame.
+      [[NSColor clearColor] set];
+      NSRectFill(dirtyRect);
+    }
 
     renderWidgetHostView_->compositing_iosurface_->DrawIOSurface(self);
     renderWidgetHostView_->AckPendingCompositorSwapBuffers();
     return;
   }
 
+  // Forget IOSurface since we are drawing a software frame now.
+  if (renderWidgetHostView_->compositing_iosurface_.get() &&
+      renderWidgetHostView_->compositing_iosurface_->HasIOSurface())
+    renderWidgetHostView_->compositing_iosurface_->UnrefIOSurface();
+
   // In case the last frame was accelerated, ack any pending swaps to unblock
   // the GPU process.
   renderWidgetHostView_->AckPendingCompositorSwapBuffers();
 
-  DCHECK(!renderWidgetHostView_->about_to_validate_and_paint_);
-
-  renderWidgetHostView_->about_to_validate_and_paint_ = true;
-  BackingStoreMac* backingStore = static_cast<BackingStoreMac*>(
-      renderWidgetHostView_->render_widget_host_->GetBackingStore(true));
-  renderWidgetHostView_->about_to_validate_and_paint_ = false;
-
   if (backingStore) {
     gfx::Rect bitmapRect(0, 0,
                          backingStore->size().width(),