Re-land^2 WebVR compositor bypass via BrowserMain context + mailbox

third_party/WebKit/Source/modules/vr/VRDisplay.cpp

Index: third_party/WebKit/Source/modules/vr/VRDisplay.cpp
diff --git a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
index cc8f1038aae5d967f3865cc8b9a1881194dcb3d9..835fd0af1239c20f73e26244da7940cec57876da 100644
--- a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
+++ b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
@@ -8,9 +8,10 @@
 #include "core/dom/DOMException.h"
 #include "core/dom/DocumentUserGestureToken.h"
 #include "core/dom/FrameRequestCallback.h"
-#include "core/dom/Fullscreen.h"
 #include "core/dom/ScriptedAnimationController.h"
 #include "core/dom/TaskRunnerHelper.h"
+#include "core/frame/FrameView.h"
+#include "core/frame/ImageBitmap.h"
 #include "core/frame/UseCounter.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/loader/DocumentLoader.h"
@@ -37,10 +38,6 @@ namespace blink {
 
 namespace {
 
-// Magic numbers used to mark valid pose index values encoded in frame
-// data. Must match the magic numbers used in vr_shell.cc.
-static constexpr std::array<uint8_t, 2> kWebVrPosePixelMagicNumbers{{42, 142}};
-
 VREye stringToVREye(const String& whichEye) {
   if (whichEye == "left")
     return VREyeLeft;
@@ -59,12 +56,8 @@ VRDisplay::VRDisplay(NavigatorVR* navigatorVR,
       m_capabilities(new VRDisplayCapabilities()),
       m_eyeParametersLeft(new VREyeParameters()),
       m_eyeParametersRight(new VREyeParameters()),
-      m_fullscreenCheckTimer(
-          TaskRunnerHelper::get(TaskType::UnspecedTimer,
-                                navigatorVR->document()->frame()),
-          this,
-          &VRDisplay::onFullscreenCheck),
       m_display(std::move(display)),
+      m_submit_frame_client_binding(this),
       m_displayClientBinding(this, std::move(request)) {}
 
 VRDisplay::~VRDisplay() {}
@@ -158,6 +151,7 @@ int VRDisplay::requestAnimationFrame(FrameRequestCallback* callback) {
   Document* doc = this->document();
   if (!doc)
     return 0;
+  VLOG(1) << __FUNCTION__ << ";;;";
   m_pendingRaf = true;
   if (!m_vrVSyncProvider.is_bound()) {
     ConnectVSyncProvider();
@@ -239,17 +233,6 @@ ScriptPromise VRDisplay::requestPresent(ScriptState* scriptState,
     return promise;
   }
 
-  // TODO(mthiesse): Remove fullscreen requirement for presentation. See
-  // crbug.com/687369
-  Document* doc = this->document();
-  if (!doc || !Fullscreen::fullscreenEnabled(*doc)) {
-    DOMException* exception =
-        DOMException::create(InvalidStateError, "Fullscreen is not enabled.");
-    resolver->reject(exception);
-    ReportPresentationResult(PresentationResult::FullscreenNotEnabled);
-    return promise;
-  }
-
   // A valid number of layers must be provided in order to present.
   if (layers.size() == 0 || layers.size() > m_capabilities->maxLayers()) {
     forceExitPresent();
@@ -395,50 +378,13 @@ void VRDisplay::beginPresent() {
     return;
   } else {
     if (m_layer.source().isHTMLCanvasElement()) {
-      HTMLCanvasElement* canvas = m_layer.source().getAsHTMLCanvasElement();
-      // TODO(klausw,crbug.com/655722): Need a proper VR compositor, but
-      // for the moment on mobile we'll just make the canvas fullscreen
-      // so that VrShell can pick it up through the standard (high
-      // latency) compositing path.      auto canvas =
-      // m_layer.source().getAsHTMLCanvasElement();
-      auto inlineStyle = canvas->inlineStyle();
-      if (inlineStyle) {
-        // THREE.js's VREffect sets explicit style.width/height on its rendering
-        // canvas based on the non-fullscreen window dimensions, and it keeps
-        // those unchanged when presenting. Unfortunately it appears that a
-        // fullscreened canvas just gets centered if it has explicitly set a
-        // size smaller than the fullscreen dimensions. Manually set size to
-        // 100% in this case and restore it when exiting fullscreen. This is a
-        // stopgap measure since THREE.js's usage appears legal according to the
-        // WebVR API spec. This will no longer be necessary once we can get rid
-        // of this fullscreen hack.
-        m_fullscreenOrigWidth = inlineStyle->getPropertyValue(CSSPropertyWidth);
-        if (!m_fullscreenOrigWidth.isNull()) {
-          canvas->setInlineStyleProperty(CSSPropertyWidth, "100%");
-        }
-        m_fullscreenOrigHeight =
-            inlineStyle->getPropertyValue(CSSPropertyHeight);
-        if (!m_fullscreenOrigHeight.isNull()) {
-          canvas->setInlineStyleProperty(CSSPropertyHeight, "100%");
-        }
-      } else {
-        m_fullscreenOrigWidth = String();
-        m_fullscreenOrigHeight = String();
-      }
-
-      if (doc) {
-        // Since the callback for requestPresent is asynchronous, we've lost our
-        // UserGestureToken, and need to create a new one to enter fullscreen.
-        gestureIndicator = WTF::wrapUnique(
-            new UserGestureIndicator(DocumentUserGestureToken::create(
-                doc, UserGestureToken::Status::PossiblyExistingGesture)));
-      }
-      Fullscreen::requestFullscreen(*canvas);
-
-      // Check to see if the canvas is still the current fullscreen
-      // element once every 2 seconds.
-      m_fullscreenCheckTimer.startRepeating(2.0, BLINK_FROM_HERE);
-      m_reenteredFullscreen = false;
+      // Stop unneeded compositor updates. We do so by hiding the view. We can't
+      // hide the page, doing so causes an assertion failure (!m_isHidden) in
+      // DrawingBuffer::prepareTextureMailboxInternal(). Do this only when we're
+      // actually presenting (m_isPresenting is true), see corresponding show()
+      // in forceExitPresent(). Otherwise the view may remain hidden for failing
+      // DON flow.
+      m_navigatorVR->document()->view()->hide();
     } else {
       DCHECK(m_layer.source().isOffscreenCanvas());
       // TODO(junov, crbug.com/695497): Implement OffscreenCanvas presentation
@@ -563,42 +509,97 @@ void VRDisplay::submitFrame() {
 
   // No frame Id to write before submitting the frame.
   if (m_vrFrameId < 0) {
-    m_display->SubmitFrame(m_framePose.Clone());
+    m_display->SubmitFrame(
+        m_framePose.Clone(),
+        m_submit_frame_client_binding.CreateInterfacePtrAndBind());
     return;
   }
 
-  // Write the frame number for the pose used into a bottom left pixel block.
-  // It is read by chrome/browser/android/vr_shell/vr_shell.cc to associate
-  // the correct corresponding pose for submission.
-  auto gl = m_contextGL;
+  m_contextGL->Flush();
+  // m_contextGL->Finish();
+  auto elem = m_layer.source();
+  ImageBitmap* image;
+  if (elem.isHTMLCanvasElement()) {
+    image = ImageBitmap::create(elem.getAsHTMLCanvasElement(),
+                                WTF::nullopt, ImageBitmapOptions());
+  } else {
+    image = ImageBitmap::create(elem.getAsOffscreenCanvas(),
+                                WTF::nullopt, ImageBitmapOptions());
+  }
+  StaticBitmapImage* bitmap = image->bitmapImage();
+  auto img = bitmap->imageForCurrentFrame(ColorBehavior::tag());
+  bitmap->ensureMailbox();
+  bitmap->transfer();
+  VLOG(1) << __FUNCTION__ << ";;; got bitmap, hasMailbox=" <<
+      bitmap->hasMailbox();
+  auto mailbox = bitmap->mailbox();
+  m_contextGL->WaitSyncTokenCHROMIUM(bitmap->syncToken().GetData());
+  VLOG(1) << __FUNCTION__ << ";;; got mailbox, name=" <<
+      (int)mailbox.name[0] << "," << (int)mailbox.name[1] << "," <<
+      (int)mailbox.name[2] << "," << (int)mailbox.name[3] << "," <<
+      (int)mailbox.name[4] << "," << (int)mailbox.name[5] << "," <<
+      (int)mailbox.name[6] << "," << (int)mailbox.name[7] << "," <<
+      (int)mailbox.name[8] << "," << (int)mailbox.name[9] << "," <<
+      (int)mailbox.name[10] << "," << (int)mailbox.name[11] << "," <<
+      (int)mailbox.name[12] << "," << (int)mailbox.name[13] << "," <<
+      (int)mailbox.name[14] << "," << (int)mailbox.name[15];
 
-  // We must ensure that the WebGL app's GL state is preserved. We do this by
-  // calling low-level GL commands directly so that the rendering context's
-  // saved parameters don't get overwritten.
+  m_framePose->mailbox = gpu::mojom::blink::Mailbox::New();
+  WTF::Vector<int8_t> tmpname(GL_MAILBOX_SIZE_CHROMIUM);
+  memcpy(&tmpname[0], &mailbox.name[0], GL_MAILBOX_SIZE_CHROMIUM);
+  m_framePose->mailbox->name = std::move(tmpname);
+  //m_prevImage = bitmap;
 
-  gl->Enable(GL_SCISSOR_TEST);
-  // Use a few pixels to ensure we get a clean color. The resolution for the
-  // WebGL buffer may not match the final rendered destination size, and
-  // texture filtering could interfere for single pixels. This isn't visible
-  // since the final rendering hides the edges via a vignette effect.
-  gl->Scissor(0, 0, 4, 4);
-  gl->ColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
-  // Careful with the arithmetic here. Float color 1.f is equivalent to int 255.
-  // Use the low byte of the index as the red component, and store an arbitrary
-  // magic number in green/blue. This number must match the reading code in
-  // vr_shell.cc. Avoid all-black/all-white.
-  gl->ClearColor((m_vrFrameId & 255) / 255.0f,
-                 kWebVrPosePixelMagicNumbers[0] / 255.0f,
-                 kWebVrPosePixelMagicNumbers[1] / 255.0f, 1.0f);
-  gl->Clear(GL_COLOR_BUFFER_BIT);
+  m_framePose->frameId = m_vrFrameId;
+  VLOG(1) << __FUNCTION__ << ";;; SubmitFrame WAIT for frame=" << m_vrFrameId;
 
-  // Set the GL state back to what was set by the WebVR application.
-  m_renderingContext->restoreScissorEnabled();
-  m_renderingContext->restoreScissorBox();
-  m_renderingContext->restoreColorMask();
-  m_renderingContext->restoreClearColor();
+  // There's two types of synchronization needed for submitting frames:
+  // - Before submitting, need to wait for the previous frame to be
+  //   pulled off the transfer surface to avoid lost frames.
+  // - After submitting, need to wait for the mailbox to be consumed,
+  //   and must remain inside the execution context while waiting.
+  while (m_pendingPreviousFrameRender) {
+    if (!m_submit_frame_client_binding.WaitForIncomingMethodCall()) {
+      LOG(ERROR) << __FUNCTION__ << ": failed to receive SubmitFrame response";
+      break;
+    }
+  }
 
-  m_display->SubmitFrame(m_framePose.Clone());
+  VLOG(1) << __FUNCTION__ << ";;; SubmitFrame START for frame=" << m_vrFrameId;
+
+  m_pendingPreviousFrameRender = true;
+  m_pendingSubmitFrame = true;
+
+  m_display->SubmitFrame(
+      m_framePose.Clone(),
+      m_submit_frame_client_binding.CreateInterfacePtrAndBind());
+  while (m_pendingSubmitFrame) {
+    if (!m_submit_frame_client_binding.WaitForIncomingMethodCall()) {
+      LOG(ERROR) << __FUNCTION__ << ": failed to receive SubmitFrame response";
+      break;
+    }
+  }
+
+#define WAIT_FOR_CURRENT_RENDER_TO_FINISH 0
+#if WAIT_FOR_CURRENT_RENDER_TO_FINISH
+  VLOG(1) << __FUNCTION__ << ";;; SubmitFrame WAIT RENDER for frame=" << m_vrFrameId;
+  while (m_pendingPreviousFrameRender) {
+    if (!m_submit_frame_client_binding.WaitForIncomingMethodCall()) {
+      LOG(ERROR) << __FUNCTION__ << ": failed to receive SubmitFrame response";
+      break;
+    }
+  }
+#endif
+
+  VLOG(1) << __FUNCTION__ << ";;; SubmitFrame DONE for frame=" << m_vrFrameId;
+}
+
+void VRDisplay::OnSubmitFrameTransferred() {
+  m_pendingSubmitFrame = false;
+}
+
+void VRDisplay::OnSubmitFrameRendered() {
+  m_pendingPreviousFrameRender = false;
 }
 
 Document* VRDisplay::document() {
@@ -636,19 +637,7 @@ void VRDisplay::stopPresenting() {
   if (m_isPresenting) {
     if (!m_capabilities->hasExternalDisplay()) {
       if (m_layer.source().isHTMLCanvasElement()) {
-        auto canvas = m_layer.source().getAsHTMLCanvasElement();
-        Fullscreen::fullyExitFullscreen(canvas->document());
-        m_fullscreenCheckTimer.stop();
-        if (!m_fullscreenOrigWidth.isNull()) {
-          canvas->setInlineStyleProperty(CSSPropertyWidth,
-                                         m_fullscreenOrigWidth);
-          m_fullscreenOrigWidth = String();
-        }
-        if (!m_fullscreenOrigHeight.isNull()) {
-          canvas->setInlineStyleProperty(CSSPropertyWidth,
-                                         m_fullscreenOrigHeight);
-          m_fullscreenOrigHeight = String();
-        }
+        m_navigatorVR->document()->view()->show();
       } else {
         // TODO(junov, crbug.com/695497): Implement for OffscreenCanvas
       }
@@ -661,6 +650,8 @@ void VRDisplay::stopPresenting() {
 
   m_renderingContext = nullptr;
   m_contextGL = nullptr;
+  m_pendingSubmitFrame = false;
+  m_pendingPreviousFrameRender = false;
 }
 
 void VRDisplay::OnActivate(device::mojom::blink::VRDisplayEventReason reason) {
@@ -723,44 +714,6 @@ void VRDisplay::ConnectVSyncProvider() {
   }
 }
 
-void VRDisplay::onFullscreenCheck(TimerBase*) {
-  DCHECK(m_layer.source().isHTMLCanvasElement());
-  if (!m_isPresenting) {
-    m_fullscreenCheckTimer.stop();
-    return;
-  }
-  // TODO: This is a temporary measure to track if fullscreen mode has been
-  // exited by the UA. If so we need to end VR presentation. Soon we won't
-  // depend on the Fullscreen API to fake VR presentation, so this will
-  // become unnessecary. Until that point, though, this seems preferable to
-  // adding a bunch of notification plumbing to Fullscreen.
-  if (!Fullscreen::isCurrentFullScreenElement(
-          *m_layer.source().getAsHTMLCanvasElement())) {
-    // TODO(mthiesse): Due to asynchronous resizing, we might get kicked out of
-    // fullscreen when changing display parameters upon entering WebVR. So one
-    // time only, we reenter fullscreen after having left it; otherwise we exit
-    // presentation.
-    if (m_reenteredFullscreen) {
-      m_isPresenting = false;
-      OnPresentChange();
-      m_fullscreenCheckTimer.stop();
-      if (m_display)
-        m_display->ExitPresent();
-      return;
-    }
-    m_reenteredFullscreen = true;
-    auto canvas = m_layer.source().getAsHTMLCanvasElement();
-    Document* doc = this->document();
-    std::unique_ptr<UserGestureIndicator> gestureIndicator;
-    if (doc) {
-      gestureIndicator = WTF::wrapUnique(
-          new UserGestureIndicator(DocumentUserGestureToken::create(
-              doc, UserGestureToken::Status::PossiblyExistingGesture)));
-    }
-    Fullscreen::requestFullscreen(*canvas);
-  }
-}
-
 ScriptedAnimationController& VRDisplay::ensureScriptedAnimationController(
     Document* doc) {
   if (!m_scriptedAnimationController)