cc: Add "lost" field to the ReturnedResource type.

When a resource is lost in a parent compositor, we inform the child
through the "lost" field in the ReturnedResource. The lost field is
passed down through intermediate parent/child compositors to its
final home.

Lost resources are considered in use by the parent who lost them
since you can not tell when you would be able to write to the texture
safely ever again at that point.

Tests:
ResourceProviderTest.LostResourceInParent
ResourceProviderTest.LostResourceInGrandParent
ResourceProviderTest.LostMailboxInParent
ResourceProviderTest.LostMailboxInGrandParent

R=piman
BUG=263069
Depends on: https://codereview.chromium.org/24078024/

Review URL: https://chromiumcodereview.appspot.com/24290003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224792 0039d316-1c4b-4281-b951-d872f2087c98

cc/resources/resource_provider.cc

@@ -110,6 +110,7 @@ ResourceProvider::Resource::Resource()
       image_id(0),
       texture_pool(0),
       wrap_mode(0),
+      lost(false),
       hint(TextureUsageAny),
       type(static_cast<ResourceType>(0)),
       format(RGBA_8888) {}
@@ -147,6 +148,7 @@ ResourceProvider::Resource::Resource(unsigned texture_id,
       image_id(0),
       texture_pool(texture_pool),
       wrap_mode(wrap_mode),
+      lost(false),
       hint(hint),
       type(GLTexture),
       format(format) {
@@ -181,6 +183,7 @@ ResourceProvider::Resource::Resource(uint8_t* pixels,
       image_id(0),
       texture_pool(0),
       wrap_mode(wrap_mode),
+      lost(false),
       hint(TextureUsageAny),
       type(Bitmap),
       format(RGBA_8888) {
@@ -226,7 +229,13 @@ ResourceProvider::~ResourceProvider() {
 
 bool ResourceProvider::InUseByConsumer(ResourceId id) {
   Resource* resource = GetResource(id);
-  return resource->lock_for_read_count > 0 || resource->exported_count > 0;
+  return resource->lock_for_read_count > 0 || resource->exported_count > 0 ||
+         resource->lost;
+}
+
+bool ResourceProvider::IsLost(ResourceId id) {
+  Resource* resource = GetResource(id);
+  return resource->lost;
 }
 
 ResourceProvider::ResourceId ResourceProvider::CreateResource(
@@ -392,7 +401,7 @@ void ResourceProvider::DeleteResource(ResourceId id) {
 void ResourceProvider::DeleteResourceInternal(ResourceMap::iterator it,
                                               DeleteStyle style) {
   Resource* resource = &it->second;
-  bool lost_resource = lost_output_surface_;
+  bool lost_resource = lost_output_surface_ || resource->lost;
 
   DCHECK(resource->exported_count == 0 || style != Normal);
   if (style == ForShutdown && resource->exported_count > 0)
@@ -624,6 +633,7 @@ const ResourceProvider::Resource* ResourceProvider::LockForWrite(
   DCHECK(!resource->lock_for_read_count);
   DCHECK_EQ(resource->exported_count, 0);
   DCHECK(!resource->external);
+  DCHECK(!resource->lost);
   DCHECK(ReadLockFenceHasPassed(resource));
   LazyAllocate(resource);
 
@@ -633,11 +643,9 @@ const ResourceProvider::Resource* ResourceProvider::LockForWrite(
 
 bool ResourceProvider::CanLockForWrite(ResourceId id) {
   Resource* resource = GetResource(id);
-  return !resource->locked_for_write &&
-      !resource->lock_for_read_count &&
-      !resource->exported_count &&
-      !resource->external &&
-      ReadLockFenceHasPassed(resource);
+  return !resource->locked_for_write && !resource->lock_for_read_count &&
+         !resource->exported_count && !resource->external && !resource->lost &&
+         ReadLockFenceHasPassed(resource);
 }
 
 void ResourceProvider::UnlockForWrite(ResourceId id) {
@@ -1020,6 +1028,7 @@ void ResourceProvider::ReceiveReturnsFromParent(
 
     CHECK_GE(resource->exported_count, returned.count);
     resource->exported_count -= returned.count;
+    resource->lost |= returned.lost;
     if (resource->exported_count)
       continue;
 
@@ -1133,7 +1142,7 @@ void ResourceProvider::DeleteAndReturnUnusedResourcesToChild(
     ResourceId child_id = child_info->parent_to_child_map[local_id];
     DCHECK(child_info->child_to_parent_map.count(child_id));
 
-    // TODO(danakj): bool is_lost = false;
+    bool is_lost = resource.lost || lost_output_surface_;
     if (resource.exported_count > 0) {
       if (style != ForShutdown) {
         // Defer this until we receive the resource back from the parent.
@@ -1142,7 +1151,7 @@ void ResourceProvider::DeleteAndReturnUnusedResourcesToChild(
       }
 
       // We still have an exported_count, so we'll have to lose it.
-      // TODO(danakj): is_lost = true;
+      is_lost = true;
     }
 
     if (resource.filter != resource.original_filter) {
@@ -1166,7 +1175,7 @@ void ResourceProvider::DeleteAndReturnUnusedResourcesToChild(
     if (!returned.sync_point)
       need_sync_point = true;
     returned.count = resource.imported_count;
-    // TODO(danakj): Save the |is_lost| bit.
+    returned.lost = is_lost;
     to_return.push_back(returned);
 
     child_info->parent_to_child_map.erase(local_id);

cc/resources/resource_provider.h

@@ -78,6 +78,7 @@ class CC_EXPORT ResourceProvider {
   // Checks whether a resource is in use by a consumer.
   bool InUseByConsumer(ResourceId id);
 
+  bool IsLost(ResourceId id);
 
   // Producer interface.
 
@@ -392,6 +393,7 @@ class CC_EXPORT ResourceProvider {
     unsigned image_id;
     GLenum texture_pool;
     GLint wrap_mode;
+    bool lost;
     TextureUsageHint hint;
     ResourceType type;
     ResourceFormat format;