Update from https://crrev.com/306655

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 if (is_posix) {
   import("//build/config/gcc/gcc_version.gni")
 }
 
+import("//build/toolchain/ccache.gni")
+
 declare_args() {
   # Normally, Android builds are lightly optimized, even for debug builds, to
   # keep binary size down. Setting this flag to true disables such optimization
   android_full_debug = false
 
   # Whether to use the binary binutils checked into third_party/binutils.
   # These are not multi-arch so cannot be used except on x86 and x86-64 (the
   # only two architectures that are currently checked in). Turn this off when
   # you are using a custom toolchain and need to control -B in cflags.
   linux_use_bundled_binutils = is_linux && cpu_arch == "x64"
+
+  # Compile in such a way as to enable profiling of the generated code. For
+  # example, don't omit the frame pointer and leave in symbols.
+  enable_profiling = false
+
+  # Compile in such a way as to make it possible for the profiler to unwind full
+  # stack frames. Setting this flag has a large effect on the performance of the
+  # generated code than just setting profiling, but gives the profiler more
+  # information to analyze.
+  # Requires profiling to be set to true.
+  enable_full_stack_frames_for_profiling = false
 }
 
 use_gold = is_linux && cpu_arch == "x64"
 
 if (!is_win) {
   # linux_use_debug_fission: whether to use split DWARF debug info
   # files. This can reduce link time significantly, but is incompatible
   # with some utilities such as icecc and ccache. Requires gold and
   # gcc >= 4.8 or clang.
   # http://gcc.gnu.org/wiki/DebugFission
-  use_debug_fission = use_gold && linux_use_bundled_binutils
+  use_debug_fission = use_gold && linux_use_bundled_binutils && !use_ccache
 }
 
 # default_include_dirs ---------------------------------------------------------
 #
 # This is a separate config so that third_party code (which would not use the
 # source root and might have conflicting versions of some headers) can remove
 # this and specify their own include paths.
 config("default_include_dirs") {
   include_dirs = [
     "//",
@@ skipping 26 matching lines @@
   # below.
   if (is_win) {
     # Windows compiler flags setup.
     # -----------------------------
     cflags += [
       "/Gy",  # Enable function-level linking.
       "/GS",  # Enable buffer security checking.
       "/FS",  # Preserve previous PDB behavior.
     ]
     if (is_component_build) {
-      cflags += [
-        "/EHsc",  # Assume C functions can't throw exceptions and don't catch
-                  # structured exceptions (only C++ ones).
-      ]
+      cflags += [ "/EHsc" ]  # Assume C functions can't throw exceptions and don't catch
+                             # structured exceptions (only C++ ones).
     }
   } else {
     # Common GCC compiler flags setup.
     # --------------------------------
-    cflags += [
-      "-fno-strict-aliasing",  # See http://crbug.com/32204
-    ]
+    cflags += [ "-fno-strict-aliasing" ]  # See http://crbug.com/32204
     cflags_cc += [
       "-fno-threadsafe-statics",
+
       # Not exporting C++ inline functions can generally be applied anywhere
       # so we do so here. Normal function visibility is controlled by
       # //build/config/gcc:symbol_visibility_hidden.
       "-fvisibility-inlines-hidden",
     ]
 
     # Stack protection.
     if (is_mac) {
       cflags += [ "-fstack-protector-all" ]
     } else if (is_linux) {
-      cflags += [ "-fstack-protector", "--param=ssp-buffer-size=4" ]
+      cflags += [
+        "-fstack-protector",
+        "--param=ssp-buffer-size=4",
+      ]
     }
 
     # Linker warnings.
     if (!(is_chromeos && cpu_arch == "arm") && !is_mac) {
       # TODO(jochen): Enable this on chromeos on arm. http://crbug.com/356580
       ldflags += [ "-Wl,--fatal-warnings" ]
     }
 
     # Common options for AddressSanitizer, LeakSanitizer, ThreadSanitizer and
     # MemorySanitizer
@@ skipping 21 matching lines @@
       "-Wno-undefined-bool-conversion",
       "-Wno-tautological-undefined-compare",
     ]
   }
 
   if (is_clang && !is_win) {
     # This is here so that all files get recompiled after a clang roll and
     # when turning clang on or off. (defines are passed via the command line,
     # and build system rebuild things when their commandline changes). Nothing
     # should ever read this define.
-    defines += [
-      "CR_CLANG_REVISION=" +
-          exec_script(
-              "//tools/clang/scripts/posix-print-revision.py", [], "value")
-    ]
+    defines += [ "CR_CLANG_REVISION=" +
+                 exec_script("//tools/clang/scripts/posix-print-revision.py",
+                             [],
+                             "value") ]
   }
 
   # Mac-specific compiler flags setup.
   # ----------------------------------
   if (is_mac || is_ios) {
     # These flags are shared between the C compiler and linker.
     common_mac_flags = []
 
     # CPU architecture.
     if (cpu_arch == "x64") {
-      common_mac_flags += [ "-arch", "x86_64" ]
+      common_mac_flags += [
+        "-arch",
+        "x86_64",
+      ]
     } else if (cpu_arch == "x86") {
-      common_mac_flags += [ "-arch", "i386" ]
+      common_mac_flags += [
+        "-arch",
+        "i386",
+      ]
     }
 
     cflags += common_mac_flags
 
     # Without this, the constructors and destructors of a C++ object inside
     # an Objective C struct won't be called, which is very bad.
-    cflags_objcc = [ "-fobjc-call-cxx-cdtors", ]
+    cflags_objcc = [ "-fobjc-call-cxx-cdtors" ]
 
     cflags_c += [ "-std=c99" ]
     cflags_cc += [ "-std=gnu++11" ]
 
     ldflags += common_mac_flags
   } else if (is_posix) {
     # Non-Mac Posix compiler flags setup.
     # -----------------------------------
     if (gcc_version >= 48) {
-      cflags_cc += [
-        "-std=gnu++11",
+      cflags_cc += [ "-std=gnu++11" ]
+    }
+
+    if (enable_profiling && !is_debug) {
+      # The GYP build spams this define into every compilation unit, as we do
+      # here, but it only appears to be used in base and a couple other places.
+      # TODO(abarth): Should we move this define closer to where it's used?
+      defines += [ "ENABLE_PROFILING" ]
+
+      cflags += [
+        "-fno-omit-frame-pointer",
+        "-g",
       ]
+
+      if (enable_full_stack_frames_for_profiling) {
+        cflags += [
+          "-fno-inline",
+          "-fno-optimize-sibling-calls",
+        ]
+      }
     }
 
     # CPU architecture. We may or may not be doing a cross compile now, so for
     # simplicity we always explicitly set the architecture.
     if (cpu_arch == "x64") {
-      cflags += [ "-m64", "-march=x86-64", ]
+      cflags += [
+        "-m64",
+        "-march=x86-64",
+      ]
       ldflags += [ "-m64" ]
     } else if (cpu_arch == "x86") {
       cflags += [ "-m32" ]
       ldflags += [ "-m32" ]
       if (is_clang) {
         cflags += [
           # Else building libyuv gives clang's register allocator issues,
           # see llvm.org/PR15798 / crbug.com/233709
           "-momit-leaf-frame-pointer",
+
           # Align the stack on 16-byte boundaries, http://crbug.com/418554.
           "-mstack-alignment=16",
           "-mstackrealign",
         ]
       }
     } else if (cpu_arch == "arm") {
       # Don't set the compiler flags for the WebView build. These will come
       # from the Android build system.
       if (!is_android_webview_build) {
         cflags += [
@@ skipping 11 matching lines @@
         }
         if (!is_clang) {
           # Clang doesn't support these flags.
           cflags += [
             # The tree-sra optimization (scalar replacement for
             # aggregates enabling subsequent optimizations) leads to
             # invalid code generation when using the Android NDK's
             # compiler (r5-r7). This can be verified using
             # webkit_unit_tests' WTF.Checked_int8_t test.
             "-fno-tree-sra",
+
             # The following option is disabled to improve binary
             # size and performance in gcc 4.9.
             "-fno-caller-saves",
           ]
         }
       }
     }
 
     defines += [ "_FILE_OFFSET_BITS=64" ]
 
@@ skipping 22 matching lines @@
       "-Wl,-z,noexecstack",
       "-Wl,-z,now",
       "-Wl,-z,relro",
     ]
   }
 
   # Linux-specific compiler flags setup.
   # ------------------------------------
   if (is_linux) {
     cflags += [ "-pthread" ]
-    ldflags += [
-      "-pthread",
-    ]
+    ldflags += [ "-pthread" ]
   }
   if (use_gold) {
     # Use gold for linking on 64-bit Linux only (on 32-bit it runs out of
     # address space, and it doesn't support cross-compiling).
     gold_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
                             root_build_dir)
     ldflags += [
       "-B$gold_path",
 
       # Newer gccs and clangs support -fuse-ld, use the flag to force gold
@@ skipping 18 matching lines @@
 
   if (linux_use_bundled_binutils) {
     binutils_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
                                 root_build_dir)
     cflags += [ "-B$binutils_path" ]
   }
 
   # Clang-specific compiler flags setup.
   # ------------------------------------
   if (is_clang) {
-    cflags += [
-      "-fcolor-diagnostics",
-    ]
-    cflags_cc += [
-      "-std=gnu++11",
-    ]
+    cflags += [ "-fcolor-diagnostics" ]
+    cflags_cc += [ "-std=gnu++11" ]
   }
 
   # Android-specific flags setup.
   # -----------------------------
   if (is_android) {
     cflags += [
       "-ffunction-sections",
       "-funwind-tables",
       "-fno-short-enums",
     ]
     if (!is_clang) {
       # Clang doesn't support these flags.
-      cflags += [
-        "-finline-limit=64",
-      ]
+      cflags += [ "-finline-limit=64" ]
     }
     if (is_android_webview_build) {
       # Android predefines this as 1; undefine it here so Chromium can redefine
       # it later to be 2 for chromium code and unset for third party code. This
       # works because cflags are added before defines.
       # TODO(brettw) the above comment seems incorrect. We specify defines
       # before cflags on our compiler command lines.
       cflags += [ "-U_FORTIFY_SOURCE" ]
     }
 
@@ skipping 10 matching lines @@
       # The NDK has these things, but doesn't define the constants
       # to say that it does. Define them here instead.
       defines += [ "HAVE_SYS_UIO_H" ]
     }
 
     # Use gold for Android for most CPU architectures.
     if (cpu_arch == "x86" || cpu_arch == "x64" || cpu_arch == "arm") {
       ldflags += [ "-fuse-ld=gold" ]
       if (is_clang) {
         # Let clang find the ld.gold in the NDK.
-        ldflags += [ "--gcc-toolchain=" + rebase_path(android_toolchain_root,
-                                                      root_build_dir) ]
+        ldflags += [ "--gcc-toolchain=" +
+                     rebase_path(android_toolchain_root, root_build_dir) ]
       }
     }
 
     ldflags += [
       "-Wl,--no-undefined",
+
       # Don't export symbols from statically linked libraries.
       "-Wl,--exclude-libs=ALL",
     ]
     if (cpu_arch == "arm") {
       ldflags += [
         # Enable identical code folding to reduce size.
         "-Wl,--icf=safe",
       ]
     }
 
     if (is_clang) {
       if (cpu_arch == "arm") {
-        cflags += [
-          "-target arm-linux-androideabi",
-        ]
+        cflags += [ "-target arm-linux-androideabi" ]
         ldflags += [ "-target arm-linux-androideabi" ]
       } else if (cpu_arch == "x86") {
         cflags += [ "-target x86-linux-androideabi" ]
         ldflags += [ "-target x86-linux-androideabi" ]
       }
     }
   }
 }
 
 config("compiler_arm_fpu") {
   if (cpu_arch == "arm" && !is_android_webview_build) {
-    cflags = [
-      "-mfpu=$arm_fpu",
-    ]
+    cflags = [ "-mfpu=$arm_fpu" ]
   }
 }
 
 # runtime_library -------------------------------------------------------------
 #
 # Sets the runtime library and associated options.
 #
 # How do you determine what should go in here vs. "compiler" above? Consider if
 # a target might choose to use a different runtime library (ignore for a moment
 # if this is possible or reasonable on your system). If such a target would want
@@ skipping 66 matching lines @@
     ]
 
     # NOTE: The stlport header include paths below are specified in cflags
     # rather than include_dirs because they need to come after include_dirs.
     # Think of them like system headers, but don't use '-isystem' because the
     # arm-linux-androideabi-4.4.3 toolchain (circa Gingerbread) will exhibit
     # strange errors. The include ordering here is important; change with
     # caution.
     android_stlport_root = "$android_ndk_root/sources/cxx-stl/stlport"
 
-    cflags += [
-      "-isystem" + rebase_path("$android_stlport_root/stlport",
-                               root_build_dir)
-    ]
-    if (arm_use_thumb) {
-      lib_dirs += [ "$android_stlport_root/libs/$android_app_abi/thumb" ]
-    } else {
-      lib_dirs += [ "$android_stlport_root/libs/$android_app_abi" ]
-    }
+    cflags += [ "-isystem" +
+                rebase_path("$android_stlport_root/stlport", root_build_dir) ]
+    lib_dirs += [ "$android_stlport_root/libs/$android_app_abi" ]
 
     if (component_mode == "shared_library") {
       libs += [ "stlport_shared" ]
     } else {
       libs += [ "stlport_static" ]
     }
 
     if (cpu_arch == "mipsel") {
       libs += [
         # ld linker is used for mips Android, and ld does not accept library
         # absolute path prefixed by "-l"; Since libgcc does not exist in mips
         # sysroot the proper library will be linked.
         # TODO(gordanac): Remove once gold linker is used for mips Android.
         "gcc",
       ]
     } else {
       libs += [
         # Manually link the libgcc.a that the cross compiler uses. This is
         # absolute because the linker will look inside the sysroot if it's not.
         rebase_path(android_libgcc_file),
       ]
     }
 
     libs += [
       "c",
       "dl",
       "m",
     ]
-
   }
 }
 
 # chromium_code ---------------------------------------------------------------
 #
 # Toggles between higher and lower warnings for code that is (or isn't)
 # part of Chromium.
 
 config("chromium_code") {
   if (is_win) {
-    cflags = [
-      "/W4",  # Warning level 4.
-    ]
+    cflags = [ "/W4" ]  # Warning level 4.
   } else {
     cflags = [
       "-Wall",
 
       # GCC turns on -Wsign-compare for C++ under -Wall, but clang doesn't,
       # so we specify it explicitly.
       # TODO(fischman): remove this if http://llvm.org/PR10448 obsoletes it.
       # http://code.google.com/p/chromium/issues/detail?id=90453
       "-Wsign-compare",
     ]
@@ skipping 77 matching lines @@
 }
 
 # Warnings ---------------------------------------------------------------------
 #
 # This is where we disable various warnings that we've decided aren't
 # worthwhile, and enable special warnings.
 
 config("default_warnings") {
   if (is_win) {
     cflags = [
-      "/WX",      # Treat warnings as errors.
-
+      "/WX",  # Treat warnings as errors.
       # Warnings permanently disabled:
 
       # TODO(GYP) The GYP build doesn't have this globally enabled but disabled
       # for a bunch of individual targets. Re-enable this globally when those
       # targets are fixed.
       "/wd4018",  # Comparing signed and unsigned values.
 
       # C4127: conditional expression is constant
       # This warning can in theory catch dead code and other problems, but
       # triggers in far too many desirable cases where the conditional
@@ skipping 34 matching lines @@
 
       # C4611: interaction between 'function' and C++ object destruction is
       #        non-portable
       # This warning is unavoidable when using e.g. setjmp/longjmp.  MSDN
       # suggests using exceptions instead of setjmp/longjmp for C++, but
       # Chromium code compiles without exception support.  We therefore have to
       # use setjmp/longjmp for e.g. JPEG decode error handling, which means we
       # have to turn off this warning (and be careful about how object
       # destruction happens in such cases).
       "/wd4611",
-
-
       # Warnings to evaluate and possibly fix/reenable later:
 
       "/wd4100",  # Unreferenced formal function parameter.
       "/wd4121",  # Alignment of a member was sensitive to packing.
       "/wd4244",  # Conversion: possible loss of data.
       "/wd4481",  # Nonstandard extension: override specifier.
       "/wd4505",  # Unreferenced local function has been removed.
       "/wd4510",  # Default constructor could not be generated.
       "/wd4512",  # Assignment operator could not be generated.
       "/wd4610",  # Class can never be instantiated, constructor required.
       "/wd4996",  # Deprecated function warning.
     ]
   } else {
     # Common GCC warning setup.
     cflags = [
       # Enables.
       "-Wendif-labels",  # Weird old-style text after an #endif.
       "-Werror",  # Warnings as errors.
 
       # Disables.
       "-Wno-missing-field-initializers",  # "struct foo f = {0};"
       "-Wno-unused-parameter",  # Unused function parameters.
     ]
     cflags_cc = []
 
     if (is_mac) {
-      cflags += [
-        "-Wnewline-eof",
-      ]
+      cflags += [ "-Wnewline-eof" ]
     }
 
     if (is_clang) {
       cflags += [
         # This warns on using ints as initializers for floats in
         # initializer lists (e.g. |int a = f(); CGSize s = { a, a };|),
         # which happens in several places in chrome code. Not sure if
         # this is worth fixing.
         "-Wno-c++11-narrowing",
 
@@ skipping 17 matching lines @@
         "-Wno-unneeded-internal-declaration",
 
         # TODO(thakis): Remove, http://crbug.com/263960
         "-Wno-reserved-user-defined-literal",
       ]
     }
     if (gcc_version >= 48) {
       cflags_cc += [
         # See comment for -Wno-c++11-narrowing.
         "-Wno-narrowing",
+
         # TODO(thakis): Remove, http://crbug.com/263960
         "-Wno-literal-suffix",
       ]
     }
 
     # Suppress warnings about ABI changes on ARM (Clang doesn't give this
     # warning).
     if (cpu_arch == "arm" && !is_clang) {
       cflags += [ "-Wno-psabi" ]
     }
 
     if (is_android) {
       # Disable any additional warnings enabled by the Android build system but
       # which chromium does not build cleanly with (when treating warning as
       # errors).
       cflags += [
         "-Wno-extra",
         "-Wno-ignored-qualifiers",
         "-Wno-type-limits",
       ]
       cflags_cc += [
         # Disabling c++0x-compat should be handled in WebKit, but
         # this currently doesn't work because gcc_version is not set
         # correctly when building with the Android build system.
         # TODO(torne): Fix this in WebKit.
         "-Wno-error=c++0x-compat",
+
         # Other things unrelated to -Wextra:
         "-Wno-non-virtual-dtor",
         "-Wno-sign-promo",
       ]
     }
 
     if (gcc_version >= 48) {
       # Don't warn about the "typedef 'foo' locally defined but not used"
       # for gcc 4.8.
       # TODO: remove this flag once all builds work. See crbug.com/227506
-      cflags += [
-        "-Wno-unused-local-typedefs",
-      ]
+      cflags += [ "-Wno-unused-local-typedefs" ]
     }
   }
 }
 
 # This will generate warnings when using Clang if code generates exit-time
 # destructors, which will slow down closing the program.
 # TODO(thakis): Make this a blacklist instead, http://crbug.com/101600
 config("wexit_time_destructors") {
   if (is_clang) {
     cflags = [ "-Wexit-time-destructors" ]
@@ skipping 10 matching lines @@
 #
 #   configs -= default_optimization_config
 #   configs += [ "//build/config/compiler/optimize_max" ]
 
 # Shared settings for both "optimize" and "optimize_max" configs.
 if (is_win) {
   common_optimize_on_cflags = [
     "/O2",
     "/Ob2",  # both explicit and auto inlining.
     "/Oy-",  # disable omitting frame pointers, must be after /o2.
-    "/Os",   # favor size over speed.
+    "/Os",  # favor size over speed.
   ]
   common_optimize_on_ldflags = []
 } else {
   common_optimize_on_cflags = [
     # Don't emit the GCC version ident directives, they just end up in the
     # .comment section taking up binary size.
     "-fno-ident",
+
     # Put data and code in their own sections, so that unused symbols
     # can be removed at link time with --gc-sections.
     "-fdata-sections",
     "-ffunction-sections",
   ]
   common_optimize_on_ldflags = []
 
   if (is_android) {
     if (!using_sanitizer) {
       common_optimize_on_cflags += [ "-fomit-frame-pointer" ]
     }
     common_optimize_on_ldflags += [
       # Warn in case of text relocations.
       "-Wl,--warn-shared-textrel",
     ]
   }
 
   if (is_mac) {
     if (symbol_level == 2) {
       # Mac dead code stripping requires symbols.
-      common_optimize_on_ldflags += [
-        "-Wl,-dead_strip",
-      ]
+      common_optimize_on_ldflags += [ "-Wl,-dead_strip" ]
     }
   } else {
     # Non-Mac Posix linker flags.
     common_optimize_on_ldflags += [
       # Specifically tell the linker to perform optimizations.
       # See http://lwn.net/Articles/192624/ .
       "-Wl,-O1",
       "-Wl,--as-needed",
       "-Wl,--gc-sections",
     ]
   }
 }
 
 # Default "optimization on" config. On Windows, this favors size over speed.
 config("optimize") {
   cflags = common_optimize_on_cflags
   ldflags = common_optimize_on_ldflags
   if (is_win) {
-    cflags += [
-      "/Os",   # favor size over speed.
-    ]
+    cflags += [ "/Os" ]  # favor size over speed.
   } else if (is_android || is_ios) {
-    cflags += [
-      "-Os",  # Favor size over speed.
-    ]
+    cflags += [ "-Os" ]  # Favor size over speed.
   } else {
-    cflags += [
-      "-O2",
-    ]
+    cflags += [ "-O2" ]
   }
 }
 
 # Turn off optimizations.
 config("no_optimize") {
   if (is_win) {
     cflags = [
       "/Od",  # Disable optimization.
       "/Ob0",  # Disable all inlining (on by default).
       "/RTC1",  # Runtime checks for stack frame and uninitialized variables.
@@ skipping 15 matching lines @@
   }
 }
 
 # Turns up the optimization level. On Windows, this implies whole program
 # optimization and link-time code generation which is very expensive and should
 # be used sparingly.
 config("optimize_max") {
   cflags = common_optimize_on_cflags
   ldflags = common_optimize_on_ldflags
   if (is_win) {
-    cflags -= [
-      "/Os",
-    ]
-    cflags += [
-      "/Ot",   # Favor speed over size.
-    ]
+    cflags -= [ "/Os" ]
+    cflags += [ "/Ot" ]  # Favor speed over size.
     if (is_official_build) {
       # TODO(GYP): TODO(dpranke): Should these only be on in an official
       # build, or on all the time? For now we'll require official build so
       # that the compile is clean.
       cflags += [
-        "/GL",   # Whole program optimization.
+        "/GL",  # Whole program optimization.
+
         # Disable Warning 4702 ("Unreachable code") for the WPO/PGO builds.
         # Probably anything that this would catch that wouldn't be caught in a
         # normal build isn't going to actually be a bug, so the incremental
         # value of C4702 for PGO builds is likely very small.
         "/wd4702",
       ]
-      ldflags += [
-        "/LTCG",
-      ]
+      ldflags += [ "/LTCG" ]
     }
   } else {
-    cflags += [
-      "-O2",
-    ]
+    cflags += [ "-O2" ]
   }
 }
 
 # Symbols ----------------------------------------------------------------------
 
 config("symbols") {
   if (is_win) {
-    cflags = [ "/Zi" ]  # Produce PDB file, no edit and continue.
+    import("//build/toolchain/goma.gni")
+    if (use_goma) {
+      cflags = [ "/Z7" ]  # No PDB file
+    } else {
+      cflags = [ "/Zi" ]  # Produce PDB file, no edit and continue.
+    }
     ldflags = [ "/DEBUG" ]
   } else {
     cflags = [ "-g2" ]
     if (use_debug_fission) {
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("minimal_symbols") {
   if (is_win) {
     # Linker symbols for backtraces only.
     ldflags = [ "/DEBUG" ]
   } else {
     cflags = [ "-g1" ]
     if (use_debug_fission) {
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }