Fix "notificiation" and "soruce" typos.

components/tracing/docs/adding_memory_infra_tracing.md

 # Adding MemoryInfra Tracing to a Component
 
 If you have a component that manages memory allocations, you should be
 registering and tracking those allocations with Chrome's MemoryInfra system.
 This lets you:
 
  * See an overview of your allocations, giving insight into total size and
    breakdown.
  * Understand how your allocations change over time and how they are impacted by
    other parts of Chrome.
@@ skipping 130 matching lines @@
 base::trace_event::MemoryAllocatorDumpGUID guid(alloc_->GetGUIDString());
 
 // From this global ID we can generate the parent allocator dump.
 base::trace_event::MemoryAllocatorDump* target_mad =
     process_memory_dump->CreateSharedGlobalAllocatorDump(guid);
 
 // We now create an ownership edge from the source dump to the target dump.
 // When creating an edge, you can assign an importance to this edge. If all
 // edges have the same importance, the size of the allocation will be split
 // between all sources which create a dump for the allocation. If one
-// edge has higher importance than the others, its soruce will be assigned the
+// edge has higher importance than the others, its source will be assigned the
 // full size of the allocation.
 const int kImportance = 1;
 process_memory_dump->AddOwnershipEdge(
     source_mad->guid(), target_mad->guid(), kImportance);
 ```
 
 If an allocation is being shared across process boundaries, it may be useful to
 generate a global ID which incorporates the ID of the local process, preventing
 two processes from generating colliding IDs. As it is not recommended to pass a
 process ID between processes for security reasons, a function
 `MemoryDumpManager::GetTracingProcessId` is provided which generates a unique ID
 per process that can be passed with the resource without security concerns.
 Frequently this ID is used to generate a global ID that is based on the
 allocated resource's ID combined with the allocating process' tracing ID.
 
 ## Suballocations
 
 Another advanced use case involves tracking sub-allocations of a larger
 allocation. For instance, this is used in
 [`gpu::gles2::TextureManager`][texture-manager] to dump both the suballocations
 which make up a texture. To create a suballocation, instead of calling
 [`ProcessMemoryDump::CreateAllocatorDump`][pmd] to create a
 [`MemoryAllocatorDump`][mem-alloc-dump], you call
 [`ProcessMemoryDump::AddSubAllocation`][pmd], providing the ID of the parent
 allocation as the first parameter.
 
 [texture-manager]: https://chromium.googlesource.com/chromium/src/+/master/gpu/command_buffer/service/texture_manager.cc