Remove unnecessary dependencies on GTM

Remove dependencies on //third_party/google_toolbox_for_mac
that are no longer used (i.e. the code do not use GTM).

Add a comment in third_party/breakpad/BUILD.gn to explain
why there is a dependency on google_toolbox_for_mac even
though there are no direct #include of any of its headers.

Bug: none
Change-Id: I297e4a6b8f4ff5b8b19f7c8d53f643547e406b8e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1901030Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713388}

remoting/host/BUILD.gn

@@ -425,10 +425,7 @@ static_library("common") {
       "Carbon.framework",
     ]
 
-    deps += [
-      ":remoting_version",
-      "//third_party/google_toolbox_for_mac",
-    ]
+    deps += [ ":remoting_version" ]
   }
 
   if (is_win) {

remoting/host/input_monitor/BUILD.gn

@@ -39,10 +39,6 @@ source_set("input_monitor") {
     deps += [ "//ui/ozone" ]
   }
 
-  if (is_mac) {
-    deps += [ "//third_party/google_toolbox_for_mac" ]
-  }
-
   if (!use_x11 || (is_chromeos && !use_ozone)) {
     sources -= [
       "local_hotkey_input_monitor_x11.cc",

third_party/breakpad/BUILD.gn

@@ -1048,6 +1048,10 @@ if (is_ios) {
     ]
 
     deps = [
+      # Breakpad includes its own copy of GTMLogger (in the file
+      # breakpad/src/common/mac/GTMLogger.m). As Chromium links
+      # to both on iOS, do not use the copy shipped with breakpad
+      # but instead use the version from google_toolbox_for_mac.
       "//third_party/google_toolbox_for_mac",
     ]