Android: Throttle render compositor if browser (compositor) is behind.

This delays the Swap ACK to the renderer if the browser has not consumed
the current frontbuffer yet.

Note: This might break embedders that don't use the browser compositor. The texture needs to be taken from RenderWidgetHostVIew through the TextureLayerClient::PrepareTexture() method.

BUG=224602,220907

Review URL: https://codereview.chromium.org/14348029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195340 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/render_widget_host_view_android.cc

@@ -77,17 +77,18 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
       content_view_core_(NULL),
       ime_adapter_android_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
       cached_background_color_(SK_ColorWHITE),
-      texture_id_in_layer_(0) {
+      texture_id_in_layer_(0),
+      consumed_current_texture_(true) {
   if (CompositorImpl::UsesDirectGL()) {
     surface_texture_transport_.reset(new SurfaceTextureTransportClient());
     layer_ = surface_texture_transport_->Initialize();
+    layer_->SetIsDrawable(true);
   } else {
-    texture_layer_ = cc::TextureLayer::Create(NULL);
+    texture_layer_ = cc::TextureLayer::Create(this);
     layer_ = texture_layer_;
   }
 
   layer_->SetContentsOpaque(true);
-  layer_->SetIsDrawable(true);
 
   host_->SetView(this);
   SetContentViewCore(content_view_core);
@@ -95,6 +96,7 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
 
 RenderWidgetHostViewAndroid::~RenderWidgetHostViewAndroid() {
   SetContentViewCore(NULL);
+  DCHECK(ack_callbacks_.empty());
   if (texture_id_in_layer_ || !last_mailbox_.IsZero()) {
     ImageTransportFactoryAndroid* factory =
         ImageTransportFactoryAndroid::GetInstance();
@@ -108,6 +110,9 @@ RenderWidgetHostViewAndroid::~RenderWidgetHostViewAndroid() {
     }
     factory->DeleteTexture(texture_id_in_layer_);
   }
+
+  if (texture_layer_)
+    texture_layer_->ClearClient();
 }
 
 
@@ -154,6 +159,8 @@ void RenderWidgetHostViewAndroid::WasShown() {
 }
 
 void RenderWidgetHostViewAndroid::WasHidden() {
+  RunAckCallbacks();
+
   if (host_->is_hidden())
     return;
 
@@ -605,7 +612,7 @@ void RenderWidgetHostViewAndroid::BuffersSwapped(
         texture_id_in_layer_, current_mailbox_.name);
   } else {
     texture_id_in_layer_ = factory->CreateTexture();
-    texture_layer_->SetTextureId(texture_id_in_layer_);
+    texture_layer_->SetIsDrawable(true);
   }
 
   ImageTransportFactoryAndroid::GetInstance()->AcquireTexture(
@@ -625,7 +632,13 @@ void RenderWidgetHostViewAndroid::BuffersSwapped(
   texture_layer_->SetUV(gfx::PointF(0, 0), uv_max);
   texture_size_in_layer_ = texture_size;
   current_mailbox_ = mailbox;
-  ack_callback.Run();
+
+  if (consumed_current_texture_ || host_->is_hidden())
+    ack_callback.Run();
+  else
+    ack_callbacks_.push(ack_callback);
+
+  consumed_current_texture_ = false;
 }
 
 void RenderWidgetHostViewAndroid::AcceleratedSurfacePostSubBuffer(
@@ -642,6 +655,7 @@ void RenderWidgetHostViewAndroid::AcceleratedSurfaceRelease() {
   // This tells us we should free the frontbuffer.
   if (texture_id_in_layer_) {
     texture_layer_->SetTextureId(0);
+    texture_layer_->SetIsDrawable(false);
     ImageTransportFactoryAndroid::GetInstance()->DeleteTexture(
         texture_id_in_layer_);
     texture_id_in_layer_ = 0;
@@ -767,6 +781,8 @@ SkColor RenderWidgetHostViewAndroid::GetCachedBackgroundColor() const {
 
 void RenderWidgetHostViewAndroid::SetContentViewCore(
     ContentViewCoreImpl* content_view_core) {
+  RunAckCallbacks();
+
   if (content_view_core_ && is_layer_attached_)
     content_view_core_->RemoveLayer(layer_);
 
@@ -775,12 +791,35 @@ void RenderWidgetHostViewAndroid::SetContentViewCore(
     content_view_core_->AttachLayer(layer_);
 }
 
+void RenderWidgetHostViewAndroid::RunAckCallbacks() {
+  while (!ack_callbacks_.empty()) {
+    ack_callbacks_.front().Run();
+    ack_callbacks_.pop();
+  }
+}
+
 void RenderWidgetHostViewAndroid::HasTouchEventHandlers(
     bool need_touch_events) {
   if (content_view_core_)
     content_view_core_->HasTouchEventHandlers(need_touch_events);
 }
 
+unsigned RenderWidgetHostViewAndroid::PrepareTexture(
+    cc::ResourceUpdateQueue* queue) {
+  RunAckCallbacks();
+  consumed_current_texture_ = true;
+  return texture_id_in_layer_;
+}
+
+WebKit::WebGraphicsContext3D* RenderWidgetHostViewAndroid::Context3d() {
+  return ImageTransportFactoryAndroid::GetInstance()->GetContext3D();
+}
+
+bool RenderWidgetHostViewAndroid::PrepareTextureMailbox(
+    cc::TextureMailbox* mailbox) {
+  return false;
+}
+
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(
     WebKit::WebScreenInfo* results) {

content/browser/renderer_host/render_widget_host_view_android.h

@@ -6,12 +6,14 @@
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_ANDROID_H_
 
 #include <map>
+#include <queue>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/i18n/rtl.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/process.h"
+#include "cc/layers/texture_layer_client.h"
 #include "content/browser/renderer_host/ime_adapter_android.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "gpu/command_buffer/common/mailbox.h"
@@ -46,7 +48,8 @@ struct NativeWebKeyboardEvent;
 // -----------------------------------------------------------------------------
 // See comments in render_widget_host_view.h about this class and its members.
 // -----------------------------------------------------------------------------
-class RenderWidgetHostViewAndroid : public RenderWidgetHostViewBase {
+class RenderWidgetHostViewAndroid : public RenderWidgetHostViewBase,
+                                    public cc::TextureLayerClient {
  public:
   RenderWidgetHostViewAndroid(RenderWidgetHostImpl* widget,
                               ContentViewCoreImpl* content_view_core);
@@ -147,6 +150,11 @@ class RenderWidgetHostViewAndroid : public RenderWidgetHostViewBase {
   virtual void ShowDisambiguationPopup(const gfx::Rect& target_rect,
                                        const SkBitmap& zoomed_bitmap) OVERRIDE;
 
+  // cc::TextureLayerClient implementation.
+  virtual unsigned PrepareTexture(cc::ResourceUpdateQueue* queue) OVERRIDE;
+  virtual WebKit::WebGraphicsContext3D* Context3d() OVERRIDE;
+  virtual bool PrepareTextureMailbox(cc::TextureMailbox* mailbox) OVERRIDE;
+
   // Non-virtual methods
   void SetContentViewCore(ContentViewCoreImpl* content_view_core);
   SkColor GetCachedBackgroundColor() const;
@@ -182,6 +190,8 @@ class RenderWidgetHostViewAndroid : public RenderWidgetHostViewBase {
                       const gfx::SizeF content_size,
                       const base::Closure& ack_callback);
 
+  void RunAckCallbacks();
+
   // The model object.
   RenderWidgetHostImpl* host_;
 
@@ -222,6 +232,10 @@ class RenderWidgetHostViewAndroid : public RenderWidgetHostViewBase {
   // The mailbox of the frame we last returned.
   gpu::Mailbox last_mailbox_;
 
+  bool consumed_current_texture_;
+
+  std::queue<base::Closure> ack_callbacks_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAndroid);
 };