Mac: Use Mavericks occlusion APIs for power savings.

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 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/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 98 matching lines @@
 
 }  // namespace
 
 // These are not documented, so use only after checking -respondsToSelector:.
 @interface NSApplication (UndocumentedSpeechMethods)
 - (void)speakString:(NSString*)string;
 - (void)stopSpeaking:(id)sender;
 - (BOOL)isSpeaking;
 @end
 
-// Declare things that are part of the 10.7 SDK.
-#if !defined(MAC_OS_X_VERSION_10_7) || \
-    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7
-
-static NSString* const NSWindowDidChangeBackingPropertiesNotification =
-    @"NSWindowDidChangeBackingPropertiesNotification";
-
-#endif  // 10.7
-
 // This method will return YES for OS X versions 10.7.3 and later, and NO
 // otherwise.
 // Used to prevent a crash when building with the 10.7 SDK and accessing the
 // notification below. See: http://crbug.com/260595.
 static BOOL SupportsBackingPropertiesChangedNotification() {
   // windowDidChangeBackingProperties: method has been added to the
   // NSWindowDelegate protocol in 10.7.3, at the same time as the
   // NSWindowDidChangeBackingPropertiesNotification notification was added.
   // If the protocol contains this method description, the notification should
   // be supported as well.
@@ skipping 374 matching lines @@
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewMac, public:
 
 RenderWidgetHostViewMac::RenderWidgetHostViewMac(RenderWidgetHost* widget,
                                                  bool is_guest_view_hack)
     : render_widget_host_(RenderWidgetHostImpl::From(widget)),
       text_input_type_(ui::TEXT_INPUT_TYPE_NONE),
       can_compose_inline_(true),
+      browser_compositor_state_(BrowserCompositorDestroyed),
       browser_compositor_view_placeholder_(
           new BrowserCompositorViewPlaceholderMac),
       is_loading_(false),
       allow_pause_for_resize_or_repaint_(true),
       is_guest_view_hack_(is_guest_view_hack),
       weak_factory_(this),
       fullscreen_parent_host_view_(NULL) {
   // |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.
@@ skipping 49 matching lines @@
 }
 
 void RenderWidgetHostViewMac::SetAllowPauseForResizeOrRepaint(bool allow) {
   allow_pause_for_resize_or_repaint_ = allow;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewMac, RenderWidgetHostView implementation:
 
 void RenderWidgetHostViewMac::EnsureBrowserCompositorView() {
-  if (browser_compositor_view_)
-    return;
-
   TRACE_EVENT0("browser",
                "RenderWidgetHostViewMac::EnsureBrowserCompositorView");
 
-  browser_compositor_view_.reset(
-      new BrowserCompositorViewMac(this, cocoa_view_, root_layer_.get()));
-  delegated_frame_host_->AddedToWindow();
-  delegated_frame_host_->WasShown(ui::LatencyInfo());
+  // Create the view, to transition from Destroyed -> Suspended.
+  if (browser_compositor_state_ == BrowserCompositorDestroyed) {
+    browser_compositor_view_.reset(
+        new BrowserCompositorViewMac(this, cocoa_view_, root_layer_.get()));
+    browser_compositor_state_ = BrowserCompositorSuspended;
+  }
+
+  // Show the DelegatedFrameHost to transition from Suspended -> Active.
+  if (browser_compositor_state_ == BrowserCompositorSuspended) {
+    delegated_frame_host_->AddedToWindow();
+    delegated_frame_host_->WasShown(ui::LatencyInfo());
+    browser_compositor_state_ = BrowserCompositorActive;
+  }
+}
+
+void RenderWidgetHostViewMac::SuspendBrowserCompositorView() {
+  TRACE_EVENT0("browser",
+               "RenderWidgetHostViewMac::SuspendBrowserCompositorView");
+
+  // Hide the DelegatedFrameHost to transition from Active -> Suspended.
+  if (browser_compositor_state_ == BrowserCompositorActive) {
+    // Marking the DelegatedFrameHost as removed from the window hierarchy is
+    // necessary to remove all connections to its old ui::Compositor.
+    delegated_frame_host_->WasHidden();
+    delegated_frame_host_->RemovingFromWindow();
+    browser_compositor_state_ = BrowserCompositorSuspended;
+  }
 }
 
 void RenderWidgetHostViewMac::DestroyBrowserCompositorView() {
   TRACE_EVENT0("browser",
                "RenderWidgetHostViewMac::DestroyBrowserCompositorView");
-  if (!browser_compositor_view_)
+
+  // Transition from Active -> Suspended if need be.
+  SuspendBrowserCompositorView();
+
+  // Destroy the BrowserCompositorView to transition Suspended -> Destroyed.
+  if (browser_compositor_state_ == BrowserCompositorSuspended) {
+    browser_compositor_view_.reset();
+    browser_compositor_state_ = BrowserCompositorDestroyed;
+  }
+}
+
+void RenderWidgetHostViewMac::DestroySuspendedBrowserCompositorViewIfNeeded() {
+  if (browser_compositor_state_ != BrowserCompositorSuspended)
     return;
 
-  // Marking the DelegatedFrameHost as removed from the window hierarchy is
-  // necessary to remove all connections to its old ui::Compositor.
-  delegated_frame_host_->WasHidden();
-  delegated_frame_host_->RemovingFromWindow();
-  browser_compositor_view_.reset();
+  // If this view is in a window that is visible, keep around the suspended
+  // BrowserCompositorView in case |cocoa_view_| is suddenly revealed (so that
+  // we don't flash white).
+  NSWindow* window = [cocoa_view_ window];
+  if (window)
+    return;
+
+  // This should only be reached if |render_widget_host_| is hidden, destroyed,
+  // or in the process of being destroyed.
+  DestroyBrowserCompositorView();
 }
 
 bool RenderWidgetHostViewMac::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RenderWidgetHostViewMac, message)
     IPC_MESSAGE_HANDLER(ViewHostMsg_PluginFocusChanged, OnPluginFocusChanged)
     IPC_MESSAGE_HANDLER(ViewHostMsg_StartPluginIme, OnStartPluginIme)
     IPC_MESSAGE_HANDLER(ViewMsg_GetRenderedTextCompleted,
         OnGetRenderedTextCompleted)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ skipping 165 matching lines @@
   // If there is not a frame being currently drawn, kick one, so that the below
   // pause will have a frame to wait on.
   render_widget_host_->ScheduleComposite();
   PauseForPendingResizeOrRepaintsAndDraw();
 }
 
 void RenderWidgetHostViewMac::WasHidden() {
   if (render_widget_host_->is_hidden())
     return;
 
-  DestroyBrowserCompositorView();
-
   // If we have a renderer, then inform it that we are being hidden so it can
   // reduce its resource utilization.
   render_widget_host_->WasHidden();
+
+  SuspendBrowserCompositorView();
+  DestroySuspendedBrowserCompositorViewIfNeeded();
 }
 
 void RenderWidgetHostViewMac::SetSize(const gfx::Size& size) {
   gfx::Rect rect = GetViewBounds();
   rect.set_size(size);
   SetBounds(rect);
 }
 
 void RenderWidgetHostViewMac::SetBounds(const gfx::Rect& rect) {
   // |rect.size()| is view coordinates, |rect.origin| is screen coordinates,
@@ skipping 2232 matching lines @@
 
   // Inserting text will delete all marked text automatically.
   hasMarkedText_ = NO;
 }
 
 - (void)insertText:(id)string {
   [self insertText:string replacementRange:NSMakeRange(NSNotFound, 0)];
 }
 
 - (void)viewDidMoveToWindow {
-  if ([self window])
+  if ([self window]) {
     [self updateScreenProperties];
+  } else {
+    // If the RenderWidgetHostViewCocoa is being removed its window, tear down

[Avi (use Gerrit), 2014/10/30 19:32:52]

s/removed its/removed from its/

[ccameron, 2014/10/30 19:52:10]

Done.

+    // its browser compositor resources, if needed.
+    renderWidgetHostView_->DestroySuspendedBrowserCompositorViewIfNeeded();
+  }
 
   if (canBeKeyView_) {
     NSWindow* newWindow = [self window];
     // Pointer comparison only, since we don't know if lastWindow_ is still
     // valid.
     if (newWindow) {
       // If we move into a new window, refresh the frame information. We
       // don't need to do it if it was the same window as it used to be in,
       // since that case is covered by WasShown(). We only want to do this for
       // real browser views, not popups.
@@ skipping 240 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end