GitLab

With gcc, ObserverList expands to 6-700 bytes every time it is 
iterated. By not trying to force OberservListBase to be inline
that shrinks some. clang already ignores the hints to inline 
the code and actually doesn't change a single bit in the generated
program with this change.

raw data:
Total change: -90875 bytes
==========================
  262 added, totalling +39188 bytes across 2 sources
  49 removed, totalling -27573 bytes across 16 sources
  23 grown, for a net change of +3600 bytes (34968 bytes before, 38568 bytes after) across 8 sources
  228 shrunk, for a net change of -106090 bytes (239819 bytes before, 133729 bytes after) across 53 sources

The additions is about 2-300 different flavours of ObserverListBase, 100-300 bytes each.

The savings are 200-600 bytes each every time an observer list is used. For example:

-870: content::RenderFrameImpl::didFailLoad(blink::WebLocalFrame*, blink::WebURLError const&) type=t, (was 1635 bytes, 
now 765 bytes)
-895: content::RenderFrameImpl::didFinishLoad(blink::WebLocalFrame*) type=t, (was 1646 bytes, now 751 bytes)
-583: content::WebContentsImpl::DidFailProvisionalLoadWithError(content::RenderFrameHostImpl*, FrameHostMsg_DidFailProvisionalLoadWithError_Params const&) type=t, (was 768 bytes, now 185 bytes)
-611: content::WebContentsImpl::DidStartProvisionalLoad(content::RenderFrameHostImpl*, GURL const&, bool, bool) type=t, (was 895 bytes, now 284 bytes)

BUG=394311

Review URL: https://codereview.chromium.org/396473004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283762 0039d316-1c4b-4281-b951-d872f2087c98