Reduce chrome.exe .text size by 50 KB with static_library

Also improves build times.

chrome.exe's .text (code) section in gn builds is about 55 KB larger
than in gyp builds (32-bit official). This is largely or completely
because of the use of source sets. The gn build links with about 320
.obj files whereas the gyp build links with ten. The linker pulls in
all of those .obj files and then fails to do a perfect job of discarding
the unused code and data.

This change gets rid of ~50 KB of this discrepancy by changing several
build targets from source_set to static_library and reducing the number
of .obj files to be linked to 72.

The size gain came from the change to components/variations, but the
other changes help to ensure that the size gain sticks, and help with
build speeds.

This change reduces the build times for relinking the affected
binaries (mostly chrome.dll and chrome_child.dll) in an official build
about 4-7%.

Some source_set targets could not be changed. These were annotated as
such to avoid wasting time on them in the future.

BUG=624274

Review-Url: https://codereview.chromium.org/2149483002
Cr-Commit-Position: refs/heads/master@{#405671}

breakpad/BUILD.gn

@@ -856,7 +856,7 @@ if (is_win) {
     }
   }
 
-  source_set("breakpad_handler") {
+  static_library("breakpad_handler") {
     configs += [ ":handler_config" ]
     if (is_win) {
       public_configs = [ ":handler_config" ]

build/secondary/third_party/crashpad/crashpad/client/BUILD.gn

@@ -6,7 +6,7 @@ config("client_config") {
   include_dirs = [ ".." ]
 }
 
-source_set("client") {
+static_library("client") {
   sources = [
     "crash_report_database.cc",
     "crash_report_database.h",

build/secondary/third_party/crashpad/crashpad/compat/BUILD.gn

@@ -19,7 +19,7 @@ config("compat_config") {
   }
 }
 
-source_set("compat") {
+static_library("compat") {
   sources = []
   if (is_mac) {
     sources += [

build/secondary/third_party/crashpad/crashpad/handler/BUILD.gn

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("handler_lib") {
+static_library("handler_lib") {
   sources = [
     "crash_report_upload_thread.cc",
     "crash_report_upload_thread.h",

build/secondary/third_party/crashpad/crashpad/minidump/BUILD.gn

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("minidump") {
+static_library("minidump") {
   deps = [
     "../compat",
     "../snapshot",

build/secondary/third_party/crashpad/crashpad/snapshot/BUILD.gn

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("snapshot") {
+static_library("snapshot") {
   deps = [
     "../client",
     "../compat",

build/secondary/third_party/crashpad/crashpad/util/BUILD.gn

@@ -35,7 +35,7 @@ if (is_mac) {
   }
 }
 
-source_set("util") {
+static_library("util") {
   sources = [
     "file/file_io.cc",
     "file/file_io.h",

build/secondary/third_party/libjpeg_turbo/BUILD.gn

@@ -100,7 +100,7 @@ if (current_cpu == "x86" || current_cpu == "x64") {
   }
 }
 
-source_set("simd") {
+static_library("simd") {
   if (current_cpu == "x86") {
     deps = [
       ":simd_asm",
@@ -141,7 +141,7 @@ config("libjpeg_config") {
   include_dirs = [ "." ]
 }
 
-source_set("libjpeg") {
+static_library("libjpeg") {
   sources = [
     "jcapimin.c",
     "jcapistd.c",

components/bookmarks/common/BUILD.gn

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("common") {
+static_library("common") {
   sources = [
     "bookmark_constants.cc",
     "bookmark_constants.h",

components/browser_watcher/BUILD.gn

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("browser_watcher") {
+static_library("browser_watcher") {
   # This is a separate lib to minimize the dependencies for its
   # hosting binary "chrome_watcher.dll".
   sources = [
@@ -20,7 +20,7 @@ source_set("browser_watcher") {
   ]
 }
 
-source_set("browser_watcher_client") {
+static_library("browser_watcher_client") {
   sources = [
     "watcher_client_win.cc",
     "watcher_client_win.h",

components/crash/content/app/BUILD.gn

@@ -27,7 +27,7 @@ static_library("lib") {
 }
 
 # GYP version: components/crash.gypi:crash_component
-source_set("app") {
+static_library("app") {
   sources = [
     "crash_switches.cc",
     "crash_switches.h",

components/variations/BUILD.gn

@@ -6,7 +6,7 @@ if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
-source_set("variations") {
+static_library("variations") {
   sources = [
     "active_field_trials.cc",
     "active_field_trials.h",

mojo/public/cpp/bindings/BUILD.gn

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("bindings") {
+static_library("bindings") {
   sources = [
     "array.h",
     "array_traits.h",

third_party/brotli/BUILD.gn

@@ -6,7 +6,7 @@ if (is_win) {
   import("//build/config/win/visual_studio_version.gni")
 }
 
-source_set("brotli") {
+static_library("brotli") {
   sources = [
     "dec/bit_reader.c",
     "dec/bit_reader.h",

third_party/libpng/BUILD.gn

@@ -33,6 +33,7 @@ config("clang_warnings") {
   }
 }
 
+# Cannot be a static_library in component builds
 source_set("libpng_sources") {
   sources = [
     "png.c",

ui/gfx/BUILD.gn

@@ -465,6 +465,7 @@ group("selection_bound") {
 }
 
 # Depend on this to use selection_bound.h without pulling in all of gfx.
+# Cannot be a static_library in component builds due to exported functions
 source_set("selection_bound_sources") {
   visibility = [ ":*" ]
 
@@ -499,6 +500,7 @@ group("memory_buffer") {
     ]
   }
 }
+# Cannot be a static_library in component builds due to exported functions
 source_set("memory_buffer_sources") {
   visibility = [ ":*" ]  # Depend on through ":memory_buffer".