Suppress invalid-heap-arg error in pdfium_unittests

Visual Studio sometimes uses new instead of new[] for array allocation,
which causes Dr. Memory report invalid-heap-arg errors.
Suppress such errors since it is not developers' problems.

TBR=tsepez@chromium.org
BUG=pdfium:287

Review URL: https://codereview.chromium.org/1473913002 .
diff --git a/tools/drmemory/suppressions.txt b/tools/drmemory/suppressions.txt
index ee85dfe..2ad8236 100644
--- a/tools/drmemory/suppressions.txt
+++ b/tools/drmemory/suppressions.txt
@@ -20,3 +20,9 @@
 *!v8::internal::Deoptimizer::ComputeOutputFrames
 *!v8::internal::`anonymous namespace'::Invoke
 *!v8::internal::Execution::Call
+
+# PDFium-i#287: new/delete[] mismatch
+INVALID HEAP ARGUMENT
+name=i#287:new-delete-array-mismatch
+drmemorylib.dll!replace_operator_delete_array
+*!NumberlikeArray<>::~NumberlikeArray<>