Create chrome_branch_deps.json for branch 6796.

Change-Id: I10f8900010e2d9cdda73d8f3743408868f6d5634
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5961727
Bot-Commit: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/6796@{#1}
Cr-Branched-From: 6c509d49-refs/heads/main@{#1373293}

chrome/chrome_branch_deps.json

+{
+  "src": "refs/branch-heads/6796",
+  "src:src/clank": "refs/heads/chromium/6796",
+  "src:src/components/optimization_guide/internal": "refs/heads/chromium/6796",
+  "src:src/internal": "refs/heads/chromium/6796",
+  "src:src/ios_internal": "refs/heads/chromium/6796",
+  "src:src/third_party/angle": "refs/heads/chromium/6796",
+  "src:src/third_party/dawn": "refs/heads/chromium/6796",
+  "src:src/third_party/devtools-frontend-internal": "refs/heads/chromium/6796",
+  "src:src/third_party/devtools-frontend-internal:devtools-frontend": "refs/heads/chromium/6796",
+  "src:src/third_party/devtools-frontend/src": "refs/heads/chromium/6796",
+  "src:src/third_party/instrumented_libs": "refs/heads/chromium/6796",
+  "src:src/third_party/openscreen/src": "refs/heads/chromium/6796",
+  "src:src/third_party/pdfium": "refs/heads/chromium/6796",
+  "src:src/third_party/vulkan-deps": "refs/heads/chromium/6796",
+  "src:src/third_party/webrtc": "refs/branch-heads/6796",
+  "src:src/v8": "refs/heads/chromium/6796"
+}