Revert of Build browser tests on all gpu release bots (patchset #1 id:1 of...

Revert of Build browser tests on all gpu release bots (patchset #1 id:1 of https://codereview.chromium.org/2841833003/ )

Reason for revert:
I don't think this CL is still needed after my fix for crbug.com/714976.

Original issue's description:
> Build browser tests on all gpu release bots
>
> Work-around as browser_tests are erroneously not rebuilt properly on
> gpu bots.
>
> BUG=chromium:714976
> TBR=kbr@chromium.org,fjhenigman@chromium.org
> CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
> NOTRY=true
>
> Review-Url: https://codereview.chromium.org/2841833003
> Cr-Commit-Position: refs/heads/master@{#467292}
> Committed: https://chromium.googlesource.com/chromium/src/+/1d0ceecfb8153cce088d62bf28d9c94c6601de91

TBR=fjhenigman@chromium.org,kbr@chromium.org,hablich@chromium.org,phajdan.jr@chromium.org,machenbach@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:714976

Review-Url: https://codereview.chromium.org/2846883004
Cr-Commit-Position: refs/heads/master@{#467921}

content/test/gpu/generate_buildbot_json.py

@@ -64,19 +64,11 @@ WATERFALL = {
   'type': Types.GPU,
 
   'builders': {
-    'GPU Win Builder' : {
-      # TODO(machenbach): Remove additional browser_tests here and on several
-      # release bots below when http://crbug.com/714976 is resolved.
-      'additional_compile_targets' : [ "browser_tests" ],
-    },
+    'GPU Win Builder' : {},
     'GPU Win Builder (dbg)' : {},
-    'GPU Mac Builder' : {
-      'additional_compile_targets' : [ "browser_tests" ],
-    },
+    'GPU Mac Builder' : {},
     'GPU Mac Builder (dbg)' : {},
-    'GPU Linux Builder' : {
-      'additional_compile_targets' : [ "browser_tests" ],
-    },
+    'GPU Linux Builder' : {},
     'GPU Linux Builder (dbg)' : {},
    },
 
@@ -179,23 +171,13 @@ FYI_WATERFALL = {
   'type': Types.GPU_FYI,
 
   'builders': {
-    'GPU Win Builder' : {
-      # TODO(machenbach): Remove additional browser_tests here and on several
-      # release bots below when http://crbug.com/714976 is resolved.
-      'additional_compile_targets' : [ "browser_tests" ],
-    },
+    'GPU Win Builder' : {},
     'GPU Win Builder (dbg)' : {},
-    'GPU Win x64 Builder' : {
-      'additional_compile_targets' : [ "browser_tests" ],
-    },
+    'GPU Win x64 Builder' : {},
     'GPU Win x64 Builder (dbg)' : {},
-    'GPU Mac Builder' : {
-      'additional_compile_targets' : [ "browser_tests" ],
-    },
+    'GPU Mac Builder' : {},
     'GPU Mac Builder (dbg)' : {},
-    'GPU Linux Builder' : {
-      'additional_compile_targets' : [ "browser_tests" ],
-    },
+    'GPU Linux Builder' : {},
     'GPU Linux Builder (dbg)' : {},
     'Linux ChromiumOS Builder' : {
       'additional_compile_targets' : [ "All" ]

testing/buildbot/chromium.gpu.fyi.json

@@ -2722,29 +2722,13 @@
       }
     ]
   },
-  "GPU Linux Builder": {
-    "additional_compile_targets": [
-      "browser_tests"
-    ]
-  },
+  "GPU Linux Builder": {},
   "GPU Linux Builder (dbg)": {},
-  "GPU Mac Builder": {
-    "additional_compile_targets": [
-      "browser_tests"
-    ]
-  },
+  "GPU Mac Builder": {},
   "GPU Mac Builder (dbg)": {},
-  "GPU Win Builder": {
-    "additional_compile_targets": [
-      "browser_tests"
-    ]
-  },
+  "GPU Win Builder": {},
   "GPU Win Builder (dbg)": {},
-  "GPU Win x64 Builder": {
-    "additional_compile_targets": [
-      "browser_tests"
-    ]
-  },
+  "GPU Win x64 Builder": {},
   "GPU Win x64 Builder (dbg)": {},
   "Linux ChromiumOS Builder": {
     "additional_compile_targets": [

testing/buildbot/chromium.gpu.json

 {
   "AAAAA1 AUTOGENERATED FILE DO NOT EDIT": {},
   "AAAAA2 See generate_buildbot_json.py to make changes": {},
-  "GPU Linux Builder": {
-    "additional_compile_targets": [
-      "browser_tests"
-    ]
-  },
+  "GPU Linux Builder": {},
   "GPU Linux Builder (dbg)": {},
-  "GPU Mac Builder": {
-    "additional_compile_targets": [
-      "browser_tests"
-    ]
-  },
+  "GPU Mac Builder": {},
   "GPU Mac Builder (dbg)": {},
-  "GPU Win Builder": {
-    "additional_compile_targets": [
-      "browser_tests"
-    ]
-  },
+  "GPU Win Builder": {},
   "GPU Win Builder (dbg)": {},
   "Linux Debug (NVIDIA)": {
     "gtest_tests": [