WebNN: Reject batched MatMul with large K dimension size on OV NPU

The OpenVINO NPU EP will take a very long time to compile models
with batched MatMul operations whose K dimension size is too large.

This CL rejects such MatMul operations to prevent WebNN from
becoming unresponsive.

Bug: 467442135
Cq-Include-Trybots: luci.chromium.try:win11-blink-rel
Change-Id: I35797f771829a2ff2908a61242a6b287e264893a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7245170
Reviewed-by: Hu, Ningxin <ningxin.hu@intel.com>
Commit-Queue: Hu, Ningxin <ningxin.hu@intel.com>
Reviewed-by: Rafael Cintron <rafael.cintron@microsoft.com>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1566584}

Author: mingmingtasd

webnn/conformance_tests/matmul.https.any.js

@@ -1081,6 +1081,60 @@ const matmulTests = [
         }
       }
     }
+  },
+  {
+    'name': 'matmul float32 2D tensors with K dimension size > 8192',
+    'graph': {
+      'inputs': {
+        'inputA': {
+          'data': new Array(2 * 8193).fill(1.0),
+          'descriptor': {shape: [2, 8193], dataType: 'float32'}
+        },
+        'inputB': {
+          'data': new Array(8193 * 2).fill(1.0),
+          'descriptor': {shape: [8193, 2], dataType: 'float32'}
+        }
+      },
+      'operators': [{
+        'name': 'matmul',
+        'arguments': [{'a': 'inputA'}, {'b': 'inputB'}],
+        'outputs': 'output'
+      }],
+      'expectedOutputs': {
+        'output': {
+          'data': [8193.0, 8193.0, 8193.0, 8193.0],
+          'descriptor': {shape: [2, 2], dataType: 'float32'}
+        }
+      }
+    }
+  },
+  {
+    'name': 'matmul float32 3D tensors with K dimension size > 8192',
+    'graph': {
+      'inputs': {
+        'inputA': {
+          'data': new Array(2 * 2 * 8193).fill(1.0),
+          'descriptor': {shape: [2, 2, 8193], dataType: 'float32'}
+        },
+        'inputB': {
+          'data': new Array(2 * 8193 * 2).fill(1.0),
+          'descriptor': {shape: [2, 8193, 2], dataType: 'float32'}
+        }
+      },
+      'operators': [{
+        'name': 'matmul',
+        'arguments': [{'a': 'inputA'}, {'b': 'inputB'}],
+        'outputs': 'output'
+      }],
+      'expectedOutputs': {
+        'output': {
+          'data': [
+            8193.0, 8193.0, 8193.0, 8193.0, 8193.0, 8193.0, 8193.0, 8193.0
+          ],
+          'descriptor': {shape: [2, 2, 2], dataType: 'float32'}
+        }
+      }
+    }
   }
 ];