gpu: Handle invalid discardable handle allocation.

R=ericrk@chromium.org

Bug: 866434
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I6c47cf25c2f15c668b50622896170886e23e6658
Reviewed-on: https://chromium-review.googlesource.com/1147253Reviewed-by: Eric Karl <ericrk@chromium.org>
Commit-Queue: Khushal <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577264}

gpu/command_buffer/client/client_font_manager.cc

@@ -60,9 +60,12 @@ ClientFontManager::~ClientFontManager() = default;
 
 SkDiscardableHandleId ClientFontManager::createHandle() {
   SkDiscardableHandleId handle_id = ++last_allocated_handle_id_;
-  discardable_handle_map_[handle_id] =
+  auto client_handle =
       client_discardable_manager_.CreateHandle(command_buffer_);
+  if (client_handle.is_null())
+    return kInvalidSkDiscardableHandleId;
 
+  discardable_handle_map_[handle_id] = client_handle;
   // Handles start with a ref-count.
   locked_handles_.insert(handle_id);
   return handle_id;
@@ -74,7 +77,9 @@ bool ClientFontManager::lockHandle(SkDiscardableHandleId handle_id) {
     return true;
 
   auto it = discardable_handle_map_.find(handle_id);
-  DCHECK(it != discardable_handle_map_.end());
+  if (it == discardable_handle_map_.end())
+    return false;
+
   bool locked = client_discardable_manager_.LockHandle(it->second);
   if (locked) {
     locked_handles_.insert(handle_id);

gpu/command_buffer/client/client_font_manager.h

@@ -36,6 +36,8 @@ class RASTER_EXPORT ClientFontManager
   SkStrikeServer* strike_server() { return &strike_server_; }
 
  private:
+  static constexpr SkDiscardableHandleId kInvalidSkDiscardableHandleId = -1;
+
   Client* client_;
   CommandBuffer* command_buffer_;
 

gpu/command_buffer/client/client_transfer_cache.cc

@@ -29,6 +29,9 @@ void ClientTransferCache::UnmapAndCreateEntry(uint32_t type, uint32_t id) {
   base::AutoLock hold(lock_);
   ClientDiscardableHandle::Id discardable_handle_id =
       discardable_manager_.CreateHandle(client_->command_buffer());
+  if (discardable_handle_id.is_null())
+    return;
+
   ClientDiscardableHandle handle =
       discardable_manager_.GetHandle(discardable_handle_id);