Add a group policy for hardware acceleration.

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 196aaf314a91d548b5a466d714d3c24bd09b8437..a2f2417c23fdc690bfcfbeef0f347f66ffadb777 100644
--- a/components/policy/resources/policy_templates.json
+++ b/components/policy/resources/policy_templates.json
@@ -123,7 +123,7 @@
 #   persistent IDs for all fields (but not for groups!) are needed. These are
 #   specified by the 'id' keys of each policy. NEVER CHANGE EXISTING IDs,
 #   because doing so would break the deployed wire format!
-#   For your editing convenience: highest ID currently used: 302
+#   For your editing convenience: highest ID currently used: 303
 #
 # Placeholders:
 #   The following placeholder strings are automatically substituted:
@@ -7397,6 +7397,26 @@
 
       Only if allowCorporateKeyUsage is set to true for an extension, it can use any platform key marked for corporate usage to sign arbitrary data. This permission should only be granted if the extension is trusted to secure access to the key against attackers.''',
     },
+    {
+      'name': 'HardwareAccelerationModeEnabled',

[bartfab (slow), 2015/07/01 09:16:54]

How does this policy interact with Disable3DAPIs?

[Zhenyao Mo, 2015/07/01 17:56:08]

Disable3DAPIs will be true if this is false. I add some text in Disable3DAPIs.

+      'type': 'main',
+      'schema': { 'type': 'boolean' },
+      'supported_on': ['chrome.*:45-', 'chrome_os:45-', 'android:45-'],
+      'features': {
+        'dynamic_refresh': False,

[bartfab (slow), 2015/07/01 09:16:54]

What happens if the policy value changes while Chrome is running? Will
content::GpuDataManager::GetInstance()->GpuAccessAllowed(NULL)'s return value
really not change?

[Zhenyao Mo, 2015/07/01 17:56:08]

This is only applied at browser startup time, so even if the value changes, it
is only effective on next browser start.

+        'per_profile': True,

[bartfab (slow), 2015/07/01 09:16:54]

Can this really be controlled on a per-profile basis? Based on the test, it
seems like it is a browser-global setting.

Also, if it is browser-global and needs to be set before the browser is created,
does the policy actually work on Chrome OS (which has no platform policy, but
cloud policy only).

[Zhenyao Mo, 2015/07/01 17:56:08]

Switched to global setting.  You are right, this should not be an option for
Chrome OS (they make sure hardware acceleration always works better than
software rendering).  I also exclude Android because I don't see a need there.
We can revisit if the needs ever arise.

+      },
+      'example_value': True,
+      'id': 303,
+      'caption': '''Use Hardware Acceleration When Available''',

[bartfab (slow), 2015/07/01 09:16:54]

Nit: Why is this in title case?

[Zhenyao Mo, 2015/07/01 17:56:08]

Switch to regular text mode.

FYI: I am simply following the example from the above Key Permissions.

[bartfab (slow), 2015/07/08 12:40:33]

I guess our template could do with a bit of clean-up :).

+      'desc': '''Use hardware acceleration when available.
+
+      If you enable this setting, hardware acceleration will be enabled unless a certain GPU feature is blacklisted.

[bartfab (slow), 2015/07/01 09:16:54]

What is that "certain GPU feature" which disables hardware acceleration? Or do
you mean that parts of the acceleration may be selectively disabled, depending
on your GPU's capabilities?

[Zhenyao Mo, 2015/07/01 17:56:07]

For example, accelerated canvas 2D, or accelerated rasterization, or accelerated
video decoding.  Each feature can be turned off independently through chrome's
software rendering list.

+
+      If you disable this setting, no hardware acceleration will be disabled.

[bartfab (slow), 2015/07/01 09:16:54]

This sentence is broken.

[Zhenyao Mo, 2015/07/01 17:56:08]

Done.

+
+      If this policy is left not set, it is equivalent to being enabled, see description above.''',

[bartfab (slow), 2015/07/01 09:16:54]

This is unnecessarily complex. How about:

If this policy is left not set, hardware acceleration will be enabled.

[Zhenyao Mo, 2015/07/01 17:56:08]

That doesn't cover the case of features being blacklisted. I think referring
back to the enabled case is easier (also the wording is copied from examples
above).

[bartfab (slow), 2015/07/08 12:40:33]

A common way to solve this is to change the first sentence to:

"If this policy is set to true or left unset, ..."

+    },
   ],
   'messages': {
     # Messages that are not associated to any policies.