Reland "[fuchsia] Switch tests to use fake-build-info & enable tests"

This is a re-land of commit 15e9ba8 /
reverts commit 57ff262.

Reason for re-land: https://fxbug.dev/121700 addresses the issues that
led to https://crbug.com/1410009 by using a different minimum shard
for system tests that need to run on devices without access to
the `fake-build-info` package.

Also update the documentation for running gtests on Core as the
`fake-build-info` package must be added.

Original change's description:
> [fuchsia] Switch tests to use fake-build-info & enable tests
>
> This reverts commit e68789b.
>
> Reason for revert: https://fxrev.dev/790735 fixes the issue
> that led to https://crbug.com/1326322.
>
> Also remove routing that was only needed by the real build-info service.
>
> Original change's description:
> > [Fuchsia] Remove dependency on fake-build-info
> >
> > Reverted last change in minimum.shard.test-cml to make it use
> > real build-info-service instead of the fake.
> > Also disabled BuildInfo test.
> >
> > Bug: 1326322
> > Change-Id: I04d70a43dd40da6a68a9ec2ddec8e4fbc6dfb881
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3652938
> > Commit-Queue: Sergey Ulanov <[email protected]>
> > Reviewed-by: David Dorwin <[email protected]>
> > Cr-Commit-Position: refs/heads/main@{#1004539}
>
> Bug: 1326322, 1326674
> Test: Tests pass on Workstation and Terminal
> Change-Id: Ia09c4fa922da87db3259abb325c469c5f2695723
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4183181
> Reviewed-by: Wez <[email protected]>
> Commit-Queue: David Dorwin <[email protected]>
> Cr-Commit-Position: refs/heads/main@{#1095887}

Bug: 1326322, 1326674
Test: base_unittests pass with all build-info references removed from Fuchsia's //src/sys/test_manager/meta/chromium_test_realm.shard.cml
Change-Id: I075a3ae40ee1d16494e90907732f264fca80c79d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4240690
Reviewed-by: Wez <[email protected]>
Commit-Queue: David Dorwin <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1108560}

base/fuchsia/system_build_info_unittest.cc

@@ -11,11 +11,7 @@ namespace base {
 
 // Ensures that when FetchAndCacheSystemInfo() has not been called in the
 // process that a  DCHECK fires to alert the developer.
-//
-// TODO(crbug.com/1326674) Ensure the test passes on Fuchsia bots and
-// re-enable.
-TEST(BuildInfoDeathTest,
-     DISABLED_GetCachedBuildInfo_DcheckIfNotAlreadyFetched) {
+TEST(BuildInfoDeathTest, GetCachedBuildInfo_DcheckIfNotAlreadyFetched) {
   // Clear the cached build info to force an error condition.
   ClearCachedSystemInfoForTesting();
 
@@ -29,9 +25,7 @@ TEST(BuildInfoDeathTest,
   EXPECT_TRUE(FetchAndCacheSystemInfo());
 }
 
-// TODO(crbug.com/1326674) Ensure the test passes on Fuchsia bots and
-// re-enable.
-TEST(BuildInfoTest, DISABLED_GetCachedBuildInfo_CheckExpectedValues) {
+TEST(BuildInfoTest, GetCachedBuildInfo_CheckExpectedValues) {
   // Ensure the cached BuildInfo is in a known state.
   ClearCachedSystemInfoForTesting();
   ASSERT_TRUE(FetchAndCacheSystemInfo());

build/config/fuchsia/test/minimum.shard.test-cml

@@ -9,23 +9,18 @@
   children: [
     {
       name: "build-info-service",
-      url: "fuchsia-pkg://fuchsia.com/build-info-service#meta/build-info.cm",
+      url: "fuchsia-pkg://fuchsia.com/fake-build-info#meta/fake_build_info.cm",
     },
     {
       name: "intl_property_manager",
       url: "fuchsia-pkg://fuchsia.com/intl_property_manager#meta/intl_property_manager.cm",
     },
   ],
   offer: [
-    {
-      directory: "build-info",
-      from: "parent",
-      to: "#build-info-service",
-    },
     {
       protocol: "fuchsia.logger.LogSink",
       from: "parent",
-      to: [ "#build-info-service", "#intl_property_manager" ],
+      to: [ "#intl_property_manager" ],
     }
   ],
   use: [
@@ -76,7 +71,7 @@
   facets: {
       "fuchsia.test": {
           "deprecated-allowed-packages": [
-             "build-info-service",
+             "fake-build-info",
              "intl_property_manager",
           ],
       },

docs/fuchsia/gtests.md

@@ -153,6 +153,13 @@ and need to be explicitly added as described in
 At a minimum, `test_manager` is required in order to run tests. This is already
 available when using a combined repo as in option (1).
 
+<!-- TODO(crbug.com/1408597): Remove this paragraph when the packages for fakes
+     are subpackaged with the tests.
+-->
+Another required package is
+`//src/developer/build_info/testing:fake-build-info`, which is not available in
+Core by default.
+
 Other useful packages include:
 * `intl_property_manager` - avoids many warnings when the test shard tries
   to launch it.
@@ -185,7 +192,7 @@ The following makes all
 [additional required packages](#additional-required-packages) available to the
 Chromium tests.
 ```bash
-$ fx set core.qemu-x64 --auto-dir --release  --with //src/testing/fidl/intl_property_manager --with //src/media/audio/audio_core
+$ fx set core.qemu-x64 --auto-dir --release --with //src/developer/build_info/testing:fake-build-info --with //src/testing/fidl/intl_property_manager --with //src/media/audio/audio_core
 ```
 
 ##### Chromium-only repo: packages in base
@@ -211,7 +218,7 @@ equivalent to the command line in [Combined repo](#combined-repo). It adds all
 It also adds `//sdk/lib/sys/cpp` to base packages to enable `base_unittests`'s
 `TestComponentContextForProcessTest.ProvideSystemService` test to pass.
 ```bash
-$ fx set core.qemu-x64 --auto-dir --release  --with-base //src/sys/test_manager --with-base //src/testing/fidl/intl_property_manager --with-base //src/media/audio/audio_core --with-base //sdk/lib/sys/cpp
+$ fx set core.qemu-x64 --auto-dir --release  --with-base //src/sys/test_manager  --with-base //src/developer/build_info/testing:fake-build-info --with-base //src/testing/fidl/intl_property_manager --with-base //src/media/audio/audio_core --with-base //sdk/lib/sys/cpp
 ```
 
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