cc: Redraw incomplete frames when new texture uploads finish

cc/scheduler_state_machine.cc

Index: cc/scheduler_state_machine.cc
diff --git a/cc/scheduler_state_machine.cc b/cc/scheduler_state_machine.cc
index d385a432a44614098fc436d82f8c366a4d42cb59..03656ef9c6c9028b8f981438fadcaa0d55fd3ed0 100644
--- a/cc/scheduler_state_machine.cc
+++ b/cc/scheduler_state_machine.cc
@@ -16,9 +16,11 @@ SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings* const sett
     , m_currentFrameNumber(0)
     , m_lastFrameNumberWhereDrawWasCalled(-1)
     , m_lastFrameNumberWhereTreeActivationAttempted(-1)
+    , m_lastFrameNumberWhereCheckForNewTexturesCalled(-1)
     , m_consecutiveFailedDraws(0)
     , m_maximumNumberOfFailedDrawsBeforeDrawIsForced(3)
     , m_needsRedraw(false)
+    , m_needsRedrawOnVisibleTextureUpload(false)
     , m_needsForcedRedraw(false)
     , m_needsForcedRedrawAfterNextCommit(false)
     , m_needsCommit(false)
@@ -39,12 +41,16 @@ SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings* const sett
 std::string SchedulerStateMachine::toString()
 {
     std::string str;
+    base::StringAppendF(&str, "m_settings.implSidePainting = %d; ", m_settings->implSidePainting);
     base::StringAppendF(&str, "m_commitState = %d; ", m_commitState);
     base::StringAppendF(&str, "m_currentFrameNumber = %d; ", m_currentFrameNumber);
     base::StringAppendF(&str, "m_lastFrameNumberWhereDrawWasCalled = %d; ", m_lastFrameNumberWhereDrawWasCalled);
+    base::StringAppendF(&str, "m_lastFrameNumberWhereTreeActivationAttempted = %d; ", m_lastFrameNumberWhereTreeActivationAttempted);
+    base::StringAppendF(&str, "m_lastFrameNumberWhereCheckForNewTexturesCalled = %d; ", m_lastFrameNumberWhereCheckForNewTexturesCalled);
     base::StringAppendF(&str, "m_consecutiveFailedDraws = %d; ", m_consecutiveFailedDraws);
     base::StringAppendF(&str, "m_maximumNumberOfFailedDrawsBeforeDrawIsForced = %d; ", m_maximumNumberOfFailedDrawsBeforeDrawIsForced);
     base::StringAppendF(&str, "m_needsRedraw = %d; ", m_needsRedraw);
+    base::StringAppendF(&str, "m_needsRedrawOnVisibleTextureUpload = %d; ", m_needsRedrawOnVisibleTextureUpload);
     base::StringAppendF(&str, "m_needsForcedRedraw = %d; ", m_needsForcedRedraw);
     base::StringAppendF(&str, "m_needsForcedRedrawAfterNextCommit = %d; ", m_needsForcedRedrawAfterNextCommit);
     base::StringAppendF(&str, "m_needsCommit = %d; ", m_needsCommit);
@@ -72,6 +78,12 @@ bool SchedulerStateMachine::hasAttemptedTreeActivationThisFrame() const
     return m_currentFrameNumber == m_lastFrameNumberWhereTreeActivationAttempted;
 }
 
+bool SchedulerStateMachine::hasCheckedForNewTexturesThisFrame() const
+{
+    return m_currentFrameNumber ==
+           m_lastFrameNumberWhereCheckForNewTexturesCalled;
+}
+
 bool SchedulerStateMachine::drawSuspendedUntilCommit() const
 {
     if (!m_canDraw)
@@ -110,7 +122,19 @@ bool SchedulerStateMachine::shouldDraw() const
 
 bool SchedulerStateMachine::shouldAttemptTreeActivation() const
 {
-  return m_hasPendingTree && m_insideVSync && !hasAttemptedTreeActivationThisFrame();
+    return m_hasPendingTree && m_insideVSync && !hasAttemptedTreeActivationThisFrame();
+}
+
+bool SchedulerStateMachine::shouldCheckForNewTextures() const
+{
+    if (!m_settings->implSidePainting)
+        return false;
+    if (hasCheckedForNewTexturesThisFrame())
+        return false;
+
+    return shouldAttemptTreeActivation() ||
+           shouldDraw() ||
+           m_needsRedrawOnVisibleTextureUpload;
 }
 
 bool SchedulerStateMachine::shouldAcquireLayerTexturesForMainThread() const
@@ -145,6 +169,8 @@ SchedulerStateMachine::Action SchedulerStateMachine::nextAction() const
             return ACTION_BEGIN_OUTPUT_SURFACE_RECREATION;
         if (m_outputSurfaceState == OUTPUT_SURFACE_RECREATING)
             return ACTION_NONE;
+        if (shouldCheckForNewTextures())
+            return ACTION_CHECK_FOR_NEW_TEXTURES;
         if (shouldAttemptTreeActivation())
             return ACTION_ACTIVATE_PENDING_TREE_IF_NEEDED;
         if (shouldDraw())
@@ -155,6 +181,8 @@ SchedulerStateMachine::Action SchedulerStateMachine::nextAction() const
         return ACTION_NONE;
 
     case COMMIT_STATE_FRAME_IN_PROGRESS:
+        if (shouldCheckForNewTextures())
+            return ACTION_CHECK_FOR_NEW_TEXTURES;
         if (shouldAttemptTreeActivation())
             return ACTION_ACTIVATE_PENDING_TREE_IF_NEEDED;
         if (shouldDraw())
@@ -165,6 +193,8 @@ SchedulerStateMachine::Action SchedulerStateMachine::nextAction() const
         return ACTION_COMMIT;
 
     case COMMIT_STATE_WAITING_FOR_FIRST_DRAW: {
+        if (shouldCheckForNewTextures())
+            return ACTION_CHECK_FOR_NEW_TEXTURES;
         if (shouldAttemptTreeActivation())
             return ACTION_ACTIVATE_PENDING_TREE_IF_NEEDED;
         if (shouldDraw() || m_outputSurfaceState == OUTPUT_SURFACE_LOST)
@@ -178,6 +208,8 @@ SchedulerStateMachine::Action SchedulerStateMachine::nextAction() const
     }
 
     case COMMIT_STATE_WAITING_FOR_FIRST_FORCED_DRAW:
+        if (shouldCheckForNewTextures())
+            return ACTION_CHECK_FOR_NEW_TEXTURES;
         if (shouldAttemptTreeActivation())
             return ACTION_ACTIVATE_PENDING_TREE_IF_NEEDED;
         if (m_needsForcedRedraw)
@@ -194,6 +226,10 @@ void SchedulerStateMachine::updateState(Action action)
     case ACTION_NONE:
         return;
 
+    case ACTION_CHECK_FOR_NEW_TEXTURES:
+        m_lastFrameNumberWhereCheckForNewTexturesCalled = m_currentFrameNumber;
+        return;
+
     case ACTION_ACTIVATE_PENDING_TREE_IF_NEEDED:
         m_lastFrameNumberWhereTreeActivationAttempted = m_currentFrameNumber;
         return;
@@ -278,6 +314,9 @@ bool SchedulerStateMachine::vsyncCallbackNeeded() const
     if (m_needsForcedRedraw)
         return true;
 
+    if (m_visible && m_needsRedrawOnVisibleTextureUpload)
+        return true;
+
     return m_needsRedraw && m_visible && m_outputSurfaceState == OUTPUT_SURFACE_ACTIVE;
 }
 
@@ -302,6 +341,11 @@ void SchedulerStateMachine::setNeedsRedraw()
     m_needsRedraw = true;
 }
 
+void SchedulerStateMachine::setNeedsRedrawOnVisibleTextureUpload()
+{
+    m_needsRedrawOnVisibleTextureUpload = true;
+}
+
 void SchedulerStateMachine::setNeedsForcedRedraw()
 {
     m_needsForcedRedraw = true;