Implemented ForceMaximizeBrowserWindowOnFirstRun policy, added unit test and browser test.

components/policy/resources/policy_templates.json

Index: components/policy/resources/policy_templates.json
diff --git a/components/policy/resources/policy_templates.json b/components/policy/resources/policy_templates.json
index da5c833869c321967f4febe29528a71ba72eb039..3087dc8749dec066dfb2d18fc4500dd3a941d4ee 100644
--- a/components/policy/resources/policy_templates.json
+++ b/components/policy/resources/policy_templates.json
@@ -7274,6 +7274,21 @@
       'desc': '''If this policy is set to false or not configured, <ph name="PRODUCT_OS_NAME">$2<ex>Google Chrome OS</ex></ph> will allow the user to shut down the device.
       If this policy is set to true, <ph name="PRODUCT_OS_NAME">$2<ex>Google Chrome OS</ex></ph> will trigger a reboot when the user shuts down the device. <ph name="PRODUCT_OS_NAME">$2<ex>Google Chrome OS</ex></ph> replaces all occurrences of shutdown buttons in the UI by reboot buttons. If the user shuts down the device using the power button, it will not automatically reboot, even if the policy is enabled.''',
     },
+    {
+      'name': 'ForceMaximizeOnFirstRun',
+      'type': 'main',
+      'schema': { 'type': 'boolean' },
+      'supported_on': ['chrome_os:43-'],
+      'features': {
+        'dynamic_refresh': False,
+        'per_profile': True,
+      },
+      'example_value': True,
+      'id': 296,
+      'caption': '''Maximize the first browser window on first run''',
+      'desc': '''If this policy is set to true, <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> will unconditionally maximize the the first window shown on first run.
+      If this policy is set to false or not configured, a heuristic will decide whether to maximize the first window shown, based on the screen size.''',
+    },
   ],
   'messages': {
     # Messages that are not associated to any policies.