tools-only Chrome Data Analysis
/app/data/chrome_data/ — Chromium Profile Persistence
Executive Summary
The chrome_data/ directory serves as the persistent user data directory for Chromium instances launched by browser_guard.py. This profile stores cookies, browsing history, extension state, and cached data across browser sessions. This enables stateful browser automation.
Directory Structure
chrome_data/
├── Default/ # Default Chrome profile
│ ├── Cache/ # HTTP response cache
│ ├── Code Cache/ # V8 bytecode cache
│ ├── Cookies # SQLite cookies database
│ ├── Cookies-journal # SQLite journal file
│ ├── DawnWebGPUCache/ # WebGPU shader cache
│ ├── Extension Scripts/ # Extension JavaScript
│ ├── Extension State/ # Extension storage
│ ├── Favicons # Favicon database
│ ├── GPUCache/ # GPU shader cache
│ ├── History # Browsing history
│ ├── History-journal # History journal
│ ├── Local Storage/ # DOM localStorage
│ ├── Login Data # Saved passwords
│ ├── Network Action Predictor # Prefetch data
│ ├── Preferences # Chrome preferences JSON
│ ├── Safe Browsing Cookies # Security cookies
│ ├── Secure Preferences # Encrypted preferences
│ ├── Session Storage/ # DOM sessionStorage
│ ├── SharedDictionary/ # Compression dictionaries
│ ├── Shortcuts # URL shortcuts
│ ├── Site Characteristics Database/ # Site behavior data
│ ├── Top Sites # New tab page tiles
│ ├── Trust Tokens # Privacy tokens
│ ├── Web Data # Autofill data
│ ├── WebStorage/ # Storage quotas
│ └── shared_proto_db/ # Protocol buffer DB
├── first_party_sets.db # First-party sets
├── GraphiteDawnCache/ # Graphite cache
├── Local State # Chrome state JSON
└── Variations # Field trial data
Data Categories
Authentication Data
The Cookies file is an SQLite database containing session tokens and login state. This is high sensitivity data. The Login Data file is an encrypted SQLite database storing saved passwords. This is also high sensitivity. Chrome's encryption uses the OS keyring on Linux. The Safe Browsing Cookies file contains security-related cookies at medium sensitivity.
Browsing History
The History file is an SQLite database containing URL history and visit counts. This is medium sensitivity. The Favicons file stores favicon images. The Shortcuts file contains typed URL shortcuts. The Top Sites file stores new tab page tiles. These are all low sensitivity.
Storage Data
The Local Storage/ directory holds persistent key-value storage through the localStorage API. This is medium sensitivity. The Session Storage/ directory contains session-scoped storage. This is low sensitivity. The WebStorage/ directory tracks storage quotas. The IndexedDB/ directory holds structured client-side storage at medium sensitivity.
Extension Data
The Extension Scripts/ directory contains extension JavaScript code. The Extension State/ directory holds extension settings and data. The ../pdf-viewer/ directory contains the PDF.js extension state.
Cache Data
The Cache/ directory stores HTTP response cache data. The Code Cache/ directory holds V8 compiled bytecode. The GPUCache/ directory contains GPU shader programs. The DawnWebGPUCache/ directory holds WebGPU shader cache. The GraphiteDawnCache/ directory contains Graphite rendering cache.
Configuration Data
The Preferences file is a JSON file containing user settings, extensions, and themes. The Secure Preferences file is an encrypted JSON file with sensitive settings. The Local State file is a JSON file containing Chrome state and profile info. The Variations file is a binary file with field trial configurations.
Operational Role
Persistence Across Sessions
# In browser_guard.py
launch_options = {
"user_data_dir": "/app/data/chrome_data",
# ...
}
This persistence provides several benefits. Cookies survive browser restarts. Login sessions remain active. Extension settings persist across sessions. Cache improves subsequent page loads. History enables navigation features.
Launch Sequence
First, browser_guard.py starts. It checks the X11 display. Then it launches Chromium with --user-data-dir=/app/data/chrome_data. Chrome reads the existing profile. Session state is restored.
Security Analysis
Sensitive Data Exposure
Session cookies present high risk. Profile isolation per user mitigates this. Saved passwords are also high risk. OS-level encryption protects them. Browsing history is medium risk. Regular cleanup reduces exposure. Autofill data is medium risk. User consent controls this. Extension data is low risk. Extension permissions limit exposure.
Multi-Tenant Considerations
Shared profiles in multi-user environments expose data across users. The recommendation is creating isolated profiles per session:
import tempfile
import shutil
# Create temp profile
profile_dir = tempfile.mkdtemp(prefix="chrome_profile_")
# Use isolated profile
launch_options["user_data_dir"] = profile_dir
# Cleanup after session
shutil.rmtree(profile_dir)
Encryption Status
The Cookies file is not encrypted. The Login Data file is encrypted using the OS keyring such as gnome-keyring or kwallet. The Secure Preferences file is encrypted with the same mechanism. The History file is not encrypted.
Inter-Module Relationships
chrome_data/
├── browser_guard.py (reads/writes)
│ └── Playwright/CDP
├── pdf-viewer/ (extension state)
│ └── PDF.js settings
└── logs/ (correlated with History)
Maintenance
Cleanup Operations
Clear the cache with rm -rf /app/data/chrome_data/Default/Cache/*. Clear cookies to log out all sessions with rm /app/data/chrome_data/Default/Cookies. Clear history with rm /app/data/chrome_data/Default/History. For a full reset, use rm -rf /app/data/chrome_data/*.
Size Monitoring
The Cache/ directory typically grows to 50 to 500 MB with linear growth based on usage. The Code Cache/ directory stabilizes at 10 to 100 MB after warmup. The History file grows slowly to 1 to 10 MB. The Cookies file grows slowly to 100 KB to 1 MB.
Troubleshooting
Chrome won't start: This is typically caused by a corrupted profile. The solution is to delete and recreate the profile.
Extension not loading: This indicates corrupt extension state. Clear the Extension State directory.
Login lost: This is expected behavior after clearing cookies.
Slow startup: This is usually caused by a large cache. Clear the Cache directory.
Document Version: 1.0 Analysis Date: 2026-02-02