[gn] Roll gn

45314e29 [metadata] Return metadata in postorder.
e49432fa [metadata] Actually collect the metadata
c1780c21 [metadata] Allow specification of rebase dir
5a9e0a2c [metadata] Adding metadata vars to write_data target
d021d391 [metadata] Add generated_file target type
27b66b57 Allow whitespace in include directives.
c6841d31 Fix a crash on invalid on `not_needed(scope)` without a 2nd argument.
54be6f11 Allow NOSORT to be the last line in a comment in addition to the first.
a07831bb (master) [metadata] Adding `meta` command
0587778f [metadata] Walk function
96c77296 [metadata] Add metadata walk to target
a27e8dc0 [metadata] Adding basic metadata walking
2000587b [metadata] Adding metadata output to gn desc
0e1b8843 [metadata] Adding metadata variable to target
ecc95221 (resolve_off_main) Add links to the "Using GN build" presentation.
13ac6ca4 Test that not_needed works with forward_variables_from
0790d304 List .gn file in build.ninja.d.
9dfbe7fd win: Slightly simplify build flags.
384850bb Explicitly handle all ValueType enum values
1426651d Make regen with --dotfile and --root work.
dd2f4cf0 [docs] Fixing broken link.
2a4d9002 gen.py: Remove UpdateLinuxSysroot()
df15af47 Explicitly specify sysroot for Linux and macOS
56b4bad8 Use Fuchsia's Clang toolchain on macOS
85d0c04b Remove all macOS specific code from base and framework dependencies
96ff462c Define C/C++ version for QtCreator project
a0108938 [recipe] Use ${platform} variable for CIPD

Change-Id: Id2bbfe888b024d0ff038bc246bafe70fb7de2f52
diff --git a/fuchsia.ensure b/fuchsia.ensure
index fbd8742..10c5ebb 100644
--- a/fuchsia.ensure
+++ b/fuchsia.ensure
@@ -13,7 +13,7 @@
 $ResolvedVersions fuchsia.versions
 
 # GN
-gn/gn/${platform} git_revision:bdb0fd02324b120cacde634a9235405061c8ea06
+gn/gn/${platform} git_revision:45314e29d54cc2e4a6501eaec860f1b09740eb9c
 
 # Ninja
 infra/ninja/${platform} version:1.8.2
diff --git a/fuchsia.versions b/fuchsia.versions
index ad2877b..40c442f 100644
--- a/fuchsia.versions
+++ b/fuchsia.versions
@@ -54,12 +54,12 @@
 	1dab9f74af2bee9727594a65fca29498e56b7ed2
 
 gn/gn/linux-amd64
-	git_revision:bdb0fd02324b120cacde634a9235405061c8ea06
-	0uGjKAZkJXPZjtYktgEwHiNbwsut_qRsk7ZCGGxi82IC
+	git_revision:45314e29d54cc2e4a6501eaec860f1b09740eb9c
+	a3Mx_U5jJsvp0XNS7lfQI0cDSib4XjFkIajzZqGTzg8C
 
 gn/gn/mac-amd64
-	git_revision:bdb0fd02324b120cacde634a9235405061c8ea06
-	rN2F641yR4Bj-H1q8OwC_RiqRpUYxy3hryzRfPER9wcC
+	git_revision:45314e29d54cc2e4a6501eaec860f1b09740eb9c
+	F5CLo3CVLBz-MUaRzrIbJJiXp2nLEqeaCb3cPluZ88AC
 
 infra/cmake/linux-amd64
 	version:3.10.0