Add a new CefBrowserHost::SetWindowlessFrameRate method to support

dynamic configuration of the windowless frame rate (issue #1629).

libcef/browser/browser_host_impl.cc

@@ -1267,6 +1267,40 @@ void CefBrowserHostImpl::NotifyMoveOrResizeStarted() {
   PlatformNotifyMoveOrResizeStarted();
 }
 
+int CefBrowserHostImpl::GetWindowlessFrameRate() {
+  // Verify that this method is being called on the UI thread.
+  if (!CEF_CURRENTLY_ON_UIT()) {
+    NOTREACHED() << "called on invalid thread";
+    return 0;
+  }
+
+  return CefRenderWidgetHostViewOSR::ClampFrameRate(
+      settings_.windowless_frame_rate);
+}
+
+void CefBrowserHostImpl::SetWindowlessFrameRate(int frame_rate) {
+  if (!CEF_CURRENTLY_ON_UIT()) {
+    CEF_POST_TASK(CEF_UIT,
+        base::Bind(&CefBrowserHostImpl::SetWindowlessFrameRate, this,
+                   frame_rate));
+    return;
+  }
+
+  if (!IsWindowless())
+    return;
+
+  settings_.windowless_frame_rate = frame_rate;
+
+  if (!web_contents())
+    return;
+
+  CefRenderWidgetHostViewOSR* view =
+      static_cast<CefRenderWidgetHostViewOSR*>(
+          web_contents()->GetRenderViewHost()->GetView());
+  if (view)
+    view->UpdateFrameRate();
+}
+
 // CefBrowser methods.
 // -----------------------------------------------------------------------------
 

libcef/browser/browser_host_impl.h

@@ -192,6 +192,8 @@ class CefBrowserHostImpl : public CefBrowserHost,
   void SendFocusEvent(bool setFocus) override;
   void SendCaptureLostEvent() override;
   void NotifyMoveOrResizeStarted() override;
+  int GetWindowlessFrameRate() override;
+  void SetWindowlessFrameRate(int frame_rate) override;
   CefTextInputContext GetNSTextInputContext() override;
   void HandleKeyEventBeforeTextInputClient(CefEventHandle keyEvent) override;
   void HandleKeyEventAfterTextInputClient(CefEventHandle keyEvent) override;

libcef/browser/render_widget_host_view_osr.cc

@@ -172,6 +172,10 @@ class CefCopyFrameGenerator {
 
   bool frame_pending() const { return frame_pending_; }
 
+  void set_frame_rate_threshold_ms(int frame_rate_threshold_ms) {
+    frame_rate_threshold_ms_ = frame_rate_threshold_ms;
+  }
+
  private:
   void InternalGenerateCopyFrame() {
     frame_pending_ = false;
@@ -375,7 +379,7 @@ class CefCopyFrameGenerator {
     }
   }
 
-  const int frame_rate_threshold_ms_;
+  int frame_rate_threshold_ms_;
   CefRenderWidgetHostViewOSR* view_;
 
   base::TimeTicks frame_start_time_;
@@ -411,6 +415,12 @@ class CefBeginFrameTimer : public cc::TimeSourceClient {
     return time_source_->Active();
   }
 
+  void SetFrameRateThresholdMs(int frame_rate_threshold_ms) {
+    time_source_->SetTimebaseAndInterval(
+        time_source_->Now(),
+        base::TimeDelta::FromMilliseconds(frame_rate_threshold_ms));
+  }
+
  private:
   // cc::TimerSourceClient implementation.
   void OnTimerTick() override {
@@ -1182,6 +1192,11 @@ void CefRenderWidgetHostViewOSR::SendFocusEvent(bool focus) {
   }
 }
 
+void CefRenderWidgetHostViewOSR::UpdateFrameRate() {
+  frame_rate_threshold_ms_ = 0;
+  SetFrameRate();
+}
+
 void CefRenderWidgetHostViewOSR::HoldResize() {
   if (!hold_resize_)
     hold_resize_ = true;
@@ -1233,6 +1248,15 @@ void CefRenderWidgetHostViewOSR::OnPaint(
   ReleaseResize();
 }
 
+// static
+int CefRenderWidgetHostViewOSR::ClampFrameRate(int frame_rate) {
+  if (frame_rate < 1)
+    return kDefaultFrameRate;
+  else if (frame_rate > kMaximumFrameRate)
+    return kMaximumFrameRate;
+  return frame_rate;
+}
+
 void CefRenderWidgetHostViewOSR::SetFrameRate() {
   DCHECK(browser_impl_.get());
   if (!browser_impl_.get())
@@ -1242,24 +1266,29 @@ void CefRenderWidgetHostViewOSR::SetFrameRate() {
   if (frame_rate_threshold_ms_ != 0)
     return;
 
-  int frame_rate = browser_impl_->settings().windowless_frame_rate;
-  if (frame_rate < 1)
-    frame_rate = kDefaultFrameRate;
-  else if (frame_rate > kMaximumFrameRate)
-    frame_rate = kMaximumFrameRate;
+  const int frame_rate =
+      ClampFrameRate(browser_impl_->settings().windowless_frame_rate);
   frame_rate_threshold_ms_ = 1000 / frame_rate;
 
   // Configure the VSync interval for the browser process.
   compositor_->vsync_manager()->SetAuthoritativeVSyncInterval(
       base::TimeDelta::FromMilliseconds(frame_rate_threshold_ms_));
 
+  if (copy_frame_generator_.get()) {
+    copy_frame_generator_->set_frame_rate_threshold_ms(
+        frame_rate_threshold_ms_);
+  }
+
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kEnableBeginFrameScheduling)) {
-    DCHECK(!begin_frame_timer_.get());
-    begin_frame_timer_.reset(new CefBeginFrameTimer(
-        frame_rate_threshold_ms_,
-        base::Bind(&CefRenderWidgetHostViewOSR::OnBeginFrameTimerTick,
-                   weak_ptr_factory_.GetWeakPtr())));
+    if (begin_frame_timer_.get()) {
+      begin_frame_timer_->SetFrameRateThresholdMs(frame_rate_threshold_ms_);
+    } else {
+      begin_frame_timer_.reset(new CefBeginFrameTimer(
+          frame_rate_threshold_ms_,
+          base::Bind(&CefRenderWidgetHostViewOSR::OnBeginFrameTimerTick,
+                     weak_ptr_factory_.GetWeakPtr())));
+    }
   }
 }
 

libcef/browser/render_widget_host_view_osr.h

@@ -234,6 +234,7 @@ class CefRenderWidgetHostViewOSR
   void SendMouseEvent(const blink::WebMouseEvent& event);
   void SendMouseWheelEvent(const blink::WebMouseWheelEvent& event);
   void SendFocusEvent(bool focus);
+  void UpdateFrameRate();
 
   void HoldResize();
   void ReleaseResize();
@@ -269,6 +270,8 @@ class CefRenderWidgetHostViewOSR
   content::RenderWidgetHostImpl* render_widget_host() const
       { return render_widget_host_; }
 
+  static int ClampFrameRate(int frame_rate);
+
  private:
   void SetFrameRate();
   void SetDeviceScaleFactor();