gpu_host_messages.h => content/gpu

content/browser/DEPS

 include_rules = [
   # Allow inclusion of specific components that we depend on. We may only
   # depend on components which we share with the mojo html_viewer.
   "+components/leveldb/public/interfaces",
   "+components/mime_util",
   "+components/mus/public/interfaces",
   "+components/mus/public",
   "+components/profile_service",
   "+components/scheduler/common",
   "+components/tracing",
   "+components/url_formatter",
 
   "+content/app/strings/grit",  # For generated headers
+  "+content/gpu",

[jam, 2016/03/22 16:50:48]

this is incorrect. content/browser should not depend on content/gpu.

for one thing, it brings in code from blink into the browser process through all
the dependencies.

if code is shared with the browser and gpu processes, it should be in
content/common. but we can't include content/gpu here, just like we can't
include content/renderer

   "+content/public/browser",
   "+device/battery",  # For battery status service.
   "+device/vibration",  # For Vibration API
   "+gin/v8_initializer.h",
   "+media/media_features.h",
   "+media/audio",  # For audio input for speech input feature.
   "+media/capture",  # For Video Device monitoring in Mac.
   "+media/base",  # For Android JNI registration.
   "+media/capture",  # For Device Monitoring
   "+media/filters",  # For reporting GPU decoding UMA.
@@ skipping 72 matching lines @@
   "+third_party/WebKit/public/web/WebSharedWorkerCreationErrors.h",
   "+third_party/WebKit/public/web/WebTextDirection.h",
   "+third_party/WebKit/public/web/WebTextInputType.h",
   "+third_party/WebKit/public/web/WebTreeScopeType.h",
   "+third_party/WebKit/public/web/mac/WebScrollbarTheme.h",
 
   # DO NOT ADD ANY CHROME OR COMPONENTS INCLUDES HERE!!!
   # See https://sites.google.com/a/chromium.org/dev/developers/content-module
   # for more information.
 ]