cc: Make scheduling be driven by vsync for android webview.

android_webview/browser/browser_view_renderer.cc

 // Copyright 2014 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 "android_webview/browser/browser_view_renderer.h"
 
 #include "android_webview/browser/browser_view_renderer_client.h"
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event_argument.h"
@@ skipping 48 matching lines @@
       compositor_(NULL),
       is_paused_(false),
       view_visible_(false),
       window_visible_(false),
       attached_to_window_(false),
       hardware_enabled_(false),
       dip_scale_(0.0),
       page_scale_factor_(1.0),
       on_new_picture_enable_(false),
       clear_view_(false),
-      compositor_needs_continuous_invalidate_(false),
-      invalidate_after_composite_(false),
-      block_invalidates_(false),
-      fallback_tick_pending_(false) {
+      compositor_needs_vsyncs_(false) {
 }
 
 BrowserViewRenderer::~BrowserViewRenderer() {
 }
 
 SharedRendererState* BrowserViewRenderer::GetAwDrawGLViewContext() {
   return &shared_renderer_state_;
 }
 
 bool BrowserViewRenderer::RequestDrawGL(bool wait_for_completion) {
@@ skipping 29 matching lines @@
 
   // Drop everything in hardware.
   if (level >= TRIM_MEMORY_MODERATE) {
     shared_renderer_state_.ReleaseHardwareDrawIfNeededOnUI();
     return;
   }
 
   // Just set the memory limit to 0 and drop all tiles. This will be reset to
   // normal levels in the next DrawGL call.
   compositor_->SetMemoryPolicy(0u);
-  ForceFakeCompositeSW();
 }
 
 size_t BrowserViewRenderer::CalculateDesiredMemoryPolicy() {
   if (g_memory_override_in_bytes)
     return static_cast<size_t>(g_memory_override_in_bytes);
 
   size_t width = last_on_draw_global_visible_rect_.width();
   size_t height = last_on_draw_global_visible_rect_.height();
   size_t bytes_limit = kMemoryMultiplier * kBytesPerPixel * width * height;
   // Round up to a multiple of kMemoryAllocationStep.
@@ skipping 36 matching lines @@
                          TRACE_EVENT_SCOPE_THREAD);
     shared_renderer_state_.SetForceInvalidateOnNextDrawGLOnUI(true);
     return true;
   }
 
   ReturnResourceFromParent();
   if (shared_renderer_state_.HasCompositorFrameOnUI()) {
     TRACE_EVENT_INSTANT0("android_webview",
                          "EarlyOut_PreviousFrameUnconsumed",
                          TRACE_EVENT_SCOPE_THREAD);
-    DidSkipCompositeInDraw();
     return true;
   }
 
   scoped_ptr<cc::CompositorFrame> frame = CompositeHw();
   if (!frame.get()) {
     TRACE_EVENT_INSTANT0("android_webview", "NoNewFrame",
                          TRACE_EVENT_SCOPE_THREAD);
     return false;
   }
 
@@ skipping 23 matching lines @@
     viewport_rect_for_tile_priority = last_on_draw_global_visible_rect_;
   }
 
   scoped_ptr<cc::CompositorFrame> frame =
       compositor_->DemandDrawHw(surface_size,
                                 gfx::Transform(),
                                 viewport,
                                 clip,
                                 viewport_rect_for_tile_priority,
                                 transform_for_tile_priority);
-  if (frame.get())
-    DidComposite();
   return frame.Pass();
 }
 
 void BrowserViewRenderer::UpdateParentDrawConstraints() {
   // Post an invalidate if the parent draw constraints are stale and there is
   // no pending invalidate.
   bool needs_force_invalidate =
       shared_renderer_state_.NeedsForceInvalidateOnNextDrawGLOnUI();
   if (needs_force_invalidate ||
       !parent_draw_constraints_.Equals(
           shared_renderer_state_.GetParentDrawConstraintsOnUI())) {
     shared_renderer_state_.SetForceInvalidateOnNextDrawGLOnUI(false);
-    EnsureContinuousInvalidation(true, needs_force_invalidate);
+    PostInvalidate();
   }
 }
 
 void BrowserViewRenderer::ReturnUnusedResource(
     scoped_ptr<cc::CompositorFrame> frame) {
   if (!frame.get())
     return;
 
   cc::CompositorFrameAck frame_ack;
   cc::TransferableResource::ReturnResources(
       frame->delegated_frame_data->resource_list, &frame_ack.resources);
   if (compositor_ && !frame_ack.resources.empty())
     compositor_->ReturnResources(frame_ack);
 }
 
 void BrowserViewRenderer::ReturnResourceFromParent() {
   cc::CompositorFrameAck frame_ack;
   shared_renderer_state_.SwapReturnedResourcesOnUI(&frame_ack.resources);
   if (compositor_ && !frame_ack.resources.empty()) {
     compositor_->ReturnResources(frame_ack);
   }
 }
 
-void BrowserViewRenderer::DidSkipCommitFrame() {
-  // Treat it the same way as skipping onDraw.
-  DidSkipCompositeInDraw();
-}
-
 void BrowserViewRenderer::InvalidateOnFunctorDestroy() {
   client_->InvalidateOnFunctorDestroy();
 }
 
 bool BrowserViewRenderer::OnDrawSoftware(SkCanvas* canvas) {
   if (!compositor_) {
     TRACE_EVENT_INSTANT0(
         "android_webview", "EarlyOut_NoCompositor", TRACE_EVENT_SCOPE_THREAD);
     return false;
   }
@@ skipping 29 matching lines @@
 }
 
 void BrowserViewRenderer::ClearView() {
   TRACE_EVENT_INSTANT0("android_webview",
                        "BrowserViewRenderer::ClearView",
                        TRACE_EVENT_SCOPE_THREAD);
   if (clear_view_)
     return;
 
   clear_view_ = true;
-  // Always invalidate ignoring the compositor to actually clear the webview.
-  EnsureContinuousInvalidation(true, false);
+  
+  PostInvalidate();
+}
+
+void BrowserViewRenderer::OnVSync(base::TimeTicks frame_time,
+    base::TimeDelta vsync_period) {
+  DCHECK(needs_vsyncs_);
+
+  if (needs_vsyncs_)
+    client_->RequestVSyncUpdate();
 }
 
 void BrowserViewRenderer::SetIsPaused(bool paused) {
   TRACE_EVENT_INSTANT1("android_webview",
                        "BrowserViewRenderer::SetIsPaused",
                        TRACE_EVENT_SCOPE_THREAD,
                        "paused",
                        paused);
   is_paused_ = paused;
-  EnsureContinuousInvalidation(false, false);
+  UpdateNeedsVSyncs();
 }
 
 void BrowserViewRenderer::SetViewVisibility(bool view_visible) {
   TRACE_EVENT_INSTANT1("android_webview",
                        "BrowserViewRenderer::SetViewVisibility",
                        TRACE_EVENT_SCOPE_THREAD,
                        "view_visible",
                        view_visible);
   view_visible_ = view_visible;
+  UpdateNeedsVSyncs();
 }
 
 void BrowserViewRenderer::SetWindowVisibility(bool window_visible) {
   TRACE_EVENT_INSTANT1("android_webview",
                        "BrowserViewRenderer::SetWindowVisibility",
                        TRACE_EVENT_SCOPE_THREAD,
                        "window_visible",
                        window_visible);
   window_visible_ = window_visible;
-  EnsureContinuousInvalidation(false, false);
+  UpdateNeedsVSyncs();
 }
 
 void BrowserViewRenderer::OnSizeChanged(int width, int height) {
   TRACE_EVENT_INSTANT2("android_webview",
                        "BrowserViewRenderer::OnSizeChanged",
                        TRACE_EVENT_SCOPE_THREAD,
                        "width",
                        width,
                        "height",
                        height);
@@ skipping 49 matching lines @@
   compositor_ = compositor;
 }
 
 void BrowserViewRenderer::DidDestroyCompositor(
     content::SynchronousCompositor* compositor) {
   TRACE_EVENT0("android_webview", "BrowserViewRenderer::DidDestroyCompositor");
   DCHECK(compositor_);
   compositor_ = NULL;
 }
 
-void BrowserViewRenderer::SetContinuousInvalidate(bool invalidate) {
-  if (compositor_needs_continuous_invalidate_ == invalidate)
-    return;
+void BrowserViewRenderer::SetNeedsVSyncs(bool needs_vsyncs) {
+  compositor_needs_vsyncs_ = needs_vsyncs;
+  UpdateNeedsVSyncs();
+}
 
-  TRACE_EVENT_INSTANT1("android_webview",
-                       "BrowserViewRenderer::SetContinuousInvalidate",
-                       TRACE_EVENT_SCOPE_THREAD,
-                       "invalidate",
-                       invalidate);
-  compositor_needs_continuous_invalidate_ = invalidate;
-
-  EnsureContinuousInvalidation(false, false);
+void BrowserViewRenderer::PostInvalidate() {
+  DCHECK(client_);
+  client_->PostInvalidate();
 }
 
 void BrowserViewRenderer::SetDipScale(float dip_scale) {
   dip_scale_ = dip_scale;
   CHECK_GT(dip_scale_, 0);
 }
 
 gfx::Vector2d BrowserViewRenderer::max_scroll_offset() const {
   DCHECK_GT(dip_scale_, 0);
   return gfx::ToCeiledVector2d(gfx::ScaleVector2d(
@@ skipping 145 matching lines @@
     overscroll_rounding_error_ = gfx::Vector2dF();
   gfx::Vector2dF scaled_overscroll_delta =
       gfx::ScaleVector2d(latest_overscroll_delta, physical_pixel_scale);
   gfx::Vector2d rounded_overscroll_delta = gfx::ToRoundedVector2d(
       scaled_overscroll_delta + overscroll_rounding_error_);
   overscroll_rounding_error_ =
       scaled_overscroll_delta - rounded_overscroll_delta;
   client_->DidOverscroll(rounded_overscroll_delta);
 }
 
-void BrowserViewRenderer::EnsureContinuousInvalidation(
-    bool force_invalidate,
-    bool skip_reschedule_tick) {
-  if (force_invalidate)
-    invalidate_after_composite_ = true;
-
-  // This method should be called again when any of these conditions change.
-  bool need_invalidate =
-      compositor_needs_continuous_invalidate_ || invalidate_after_composite_;
-  if (!need_invalidate || block_invalidates_)
-    return;
-
-  if (!compositor_needs_continuous_invalidate_ && invalidate_after_composite_)
-    invalidate_after_composite_ = false;
-
-  // Always call view invalidate. We rely the Android framework to ignore the
-  // invalidate when it's not needed such as when view is not visible.
-  client_->PostInvalidate();
-
-  // Stop fallback ticks when one of these is true.
-  // 1) Webview is paused. Also need to check we are not in clear view since
-  // paused, offscreen still expect clear view to recover.
-  // 2) If we are attached to window and the window is not visible (eg when
-  // app is in the background). We are sure in this case the webview is used
-  // "on-screen" but that updates are not needed when in the background.
-  bool throttle_fallback_tick =
-      (is_paused_ && !clear_view_) || (attached_to_window_ && !window_visible_);
-  if (throttle_fallback_tick)
-    return;
-
-  block_invalidates_ = compositor_needs_continuous_invalidate_;
-  if (skip_reschedule_tick && fallback_tick_pending_)
-    return;
-
-  // Unretained here is safe because the callbacks are cancelled when
-  // they are destroyed.
-  post_fallback_tick_.Reset(base::Bind(&BrowserViewRenderer::PostFallbackTick,
-                                       base::Unretained(this)));
-  fallback_tick_fired_.Cancel();
-  fallback_tick_pending_ = false;
-
-  // No need to reschedule fallback tick if compositor does not need to be
-  // ticked. This can happen if this is reached because force_invalidate is
-  // true.
-  if (compositor_needs_continuous_invalidate_) {
-    fallback_tick_pending_ = true;
-    ui_task_runner_->PostTask(FROM_HERE, post_fallback_tick_.callback());
-  }
-}
-
-void BrowserViewRenderer::PostFallbackTick() {
-  DCHECK(fallback_tick_fired_.IsCancelled());
-  fallback_tick_fired_.Reset(base::Bind(&BrowserViewRenderer::FallbackTickFired,
-                                        base::Unretained(this)));
-  if (compositor_needs_continuous_invalidate_) {
-    ui_task_runner_->PostDelayedTask(
-        FROM_HERE,
-        fallback_tick_fired_.callback(),
-        base::TimeDelta::FromMilliseconds(kFallbackTickTimeoutInMilliseconds));
-  } else {
-    // Pretend we just composited to unblock further invalidates.
-    DidComposite();
-  }
-}
-
-void BrowserViewRenderer::FallbackTickFired() {
-  TRACE_EVENT1("android_webview",
-               "BrowserViewRenderer::FallbackTickFired",
-               "compositor_needs_continuous_invalidate_",
-               compositor_needs_continuous_invalidate_);
-
-  // This should only be called if OnDraw or DrawGL did not come in time, which
-  // means block_invalidates_ must still be true.
-  DCHECK(block_invalidates_);
-  fallback_tick_pending_ = false;
-  if (compositor_needs_continuous_invalidate_ && compositor_) {
-    if (hardware_enabled_) {
-      ReturnResourceFromParent();
-      ReturnUnusedResource(shared_renderer_state_.PassUncommittedFrameOnUI());
-      scoped_ptr<cc::CompositorFrame> frame = CompositeHw();
-      if (frame.get()) {
-        shared_renderer_state_.SetCompositorFrameOnUI(frame.Pass(), true);
-      }
-    } else {
-      ForceFakeCompositeSW();
-    }
-  } else {
-    // Pretend we just composited to unblock further invalidates.
-    DidComposite();
-  }
-}
-
-void BrowserViewRenderer::ForceFakeCompositeSW() {
-  DCHECK(compositor_);
-  SkBitmap bitmap;
-  bitmap.allocN32Pixels(1, 1);
-  bitmap.eraseColor(0);
-  SkCanvas canvas(bitmap);
-  CompositeSW(&canvas);
-}
-
 bool BrowserViewRenderer::CompositeSW(SkCanvas* canvas) {
   DCHECK(compositor_);
   ReturnResourceFromParent();
-  bool result = compositor_->DemandDrawSw(canvas);
-  DidComposite();
-  return result;
+  return compositor_->DemandDrawSw(canvas);
 }
 
-void BrowserViewRenderer::DidComposite() {
-  block_invalidates_ = false;
-  post_fallback_tick_.Cancel();
-  fallback_tick_fired_.Cancel();
-  fallback_tick_pending_ = false;
-  EnsureContinuousInvalidation(false, false);
-}
+void BrowserViewRenderer::UpdateNeedsVSyncs() {
+  bool needs_vsyncs = !is_paused_ && IsVisible() && compositor_needs_vsyncs_;
 
-void BrowserViewRenderer::DidSkipCompositeInDraw() {
-  block_invalidates_ = false;
-  EnsureContinuousInvalidation(true, true);
+  if (needs_vsyncs_ == needs_vsyncs)
+    return;
+
+  needs_vsyncs_ = needs_vsyncs;
+
+  if (needs_vsyncs_)
+    client_->RequestVSyncUpdate();
 }
 
 std::string BrowserViewRenderer::ToString() const {
   std::string str;
   base::StringAppendF(&str, "is_paused: %d ", is_paused_);
   base::StringAppendF(&str, "view_visible: %d ", view_visible_);
   base::StringAppendF(&str, "window_visible: %d ", window_visible_);
   base::StringAppendF(&str, "dip_scale: %f ", dip_scale_);
   base::StringAppendF(&str, "page_scale_factor: %f ", page_scale_factor_);
   base::StringAppendF(&str,
-                      "compositor_needs_continuous_invalidate: %d ",
-                      compositor_needs_continuous_invalidate_);
-  base::StringAppendF(&str, "block_invalidates: %d ", block_invalidates_);
+                      "compositor_needs_vsyncs_: %d ",
+                      compositor_needs_vsyncs_);
   base::StringAppendF(&str, "view size: %s ", size_.ToString().c_str());
   base::StringAppendF(&str, "attached_to_window: %d ", attached_to_window_);
   base::StringAppendF(&str,
                       "global visible rect: %s ",
                       last_on_draw_global_visible_rect_.ToString().c_str());
   base::StringAppendF(
       &str, "scroll_offset_dip: %s ", scroll_offset_dip_.ToString().c_str());
   base::StringAppendF(&str,
                       "overscroll_rounding_error_: %s ",
                       overscroll_rounding_error_.ToString().c_str());
   base::StringAppendF(
       &str, "on_new_picture_enable: %d ", on_new_picture_enable_);
   base::StringAppendF(&str, "clear_view: %d ", clear_view_);
   return str;
 }
 
 }  // namespace android_webview