Align trace event allocations to avoid alignment issues on 32-bit ARM

Bug: skia:8463
Change-Id: Ic30f36e2a7cc2b96c307fd9ce8454fddce655115
Reviewed-on: https://skia-review.googlesource.com/c/164692
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

tools/trace/SkChromeTracingTracer.cpp

@@ -105,6 +105,8 @@ SkEventTracer::Handle SkChromeTracingTracer::addTraceEvent(char phase,
         }
     }
 
+    size = SkAlign8(size);
+
     SkSTArray<128, uint8_t, true> storage;
     uint8_t* storagePtr = storage.push_back_n(size);